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Deep-sea benthic communities from the Weddell Sea, Antarctica, were sampled in January–April 2005 in an area located between 61°S–70°S and 0°W–49°W. We found a total of eight ascidian species that belong to five different families, of which one corresponded to a new species. These were: Protoholozoa pedunculata Kott, 1969; Corynascidia suhmi Herdman, 1882; Styela andeepensis Maggioni & Tatián sp. nov.; Culeolus suhmi Herman, 1881; Culeolus anonymus Monniot F. & Monniot C., 1976; Culeolus likae Sanamyan K. & Sanamyan N., 2002; Oligotrema lyra (Monniot C. & Monniot F., 1973) and Asajirus indicus (Oka, 1913). We report: the extension of the known distribution ranges of P. pedunculata, Corynascidia suhmi, Culeolus suhmi, C. likae and A. indicus, being the first time they are collected from the Weddell Sea; and the shallowest record of C. likae. Six species were added to the list of ascidians of the Weddell Sea, being all deep-sea representatives. While the total number of ascidian species augmented from 43 to 49, the number of deep-sea representatives increased from 23 to 29. Our findings, thus, reinforce the need of performing more deep-sea prospections in the area.

Culeolus herdmani Sluiter, 1904 Figure 16 Monniot C. & Monniot F. 1991 and synonymy. Monniot F. & Monniot C. 2003. Monniot F. 2021. Stations: SPANBIOS: CP 5146; CP 5147; CP 5150; CP 5178; CP 5185; CP 5189; CP 5200; CP 5217; CP 5219; CP 5231; CP 5232; CP 5267; DW 5230; DW 5236. Stations EXBODI: CP 3786; CP 3805; CP 3810; CP 3824; CP 3833; CP 3836; CP 3839; DW 3785. Very common in the western tropical Pacific region C. herdmani was found as deep as 1700m depth (Monniot C. & Monniot F. 1991) but is particularly abundant between 400–500 m. The body shape is always the same. The head is naked with small scattered buttons on the tunic surface and a ring of papillae at some distance from the atrial aperture. The oral siphon is close to the curved origin of the peduncle. The atrial opening is at mid distance of the head length. The peduncle is narrow, stiff and long, with a longitudinal groove and is totally encrusted with sediment. The internal anatomy is constant even in small specimens. There are four branchial folds on each side and a long open gut loop (Fig. 16A) ending in a multilobed anus. There are two gonads on each side with a characteristic disposition (Fig. 16A,B) and one endocarp on each body side. The musculature covers the whole body (Fig. 16C,D) with large fibres particularly dense around the siphon apertures., Published as part of Exbodi, Françoise Monniot, 2022, Additional records of bathyal ascidians (Tunicata) from the New Caledonia region, pp. 201-223 in Zootaxa 5195 (3) on pages 218-219, DOI: 10.11646/zootaxa.5195.3.1, http://zenodo.org/record/7187776, {"references":["Sluiter, C. P. (1904) Die Tunicaten der Siboga expedition Pt. 1 Die socialen und holosomen Ascidien. Siboga Expedition, 56 A, 1 - 139."]}

Exbodi, Françoise Monniot (2022): Additional records of bathyal ascidians (Tunicata) from the New Caledonia region. Zootaxa 5195 (3): 201-223, DOI: https://doi.org/10.11646/zootaxa.5195.3.1

Herdmania pennata (Monniot C. & Monniot F. 1991) Figure 17 Pyura pennata Monniot C. & Monniot F. 1991 Herdmania pennata (Monniot F. & Monniot C. 2003) Station: SPANBIOS: CP 5156, 1 specimen. The body (Fig. 17A), 14mm in diameter, is soft with a naked tunic with short spicules. The body wall and all internal organs contain verticill spindle-like spicules characteristic of the genus. There are three sizes of ramified oral tentacles. In addition to the siphon sphincters the body wall musculature consists of a few longitudinal ribbons issued from the oral and atrial siphons but which do not reach the ventral body side. Their design is the same as previously figured (Monniot C. & F. 1991 Fig. 28A). The branchial sac (Fig. 17B) has high folds, nine on the right side and eight plus one incomplete fold on the left side. The digestive loop is open; the hepatic gland has round papillae. There is a long gonad on each side (Fig. 17B). The testis vesicles surround the tubular ovary. The long sperm duct running along the ovary has a distal opening as well as additional lateral openings on erect papillae (Monniot C. & Monniot F. 1991 Fig. 28B). The oviduct opens in a wide terminal corolla. There are no endocarps. The anatomy of this single specimen corresponds to re-examined older samples of this species., Published as part of Exbodi, Françoise Monniot, 2022, Additional records of bathyal ascidians (Tunicata) from the New Caledonia region, pp. 201-223 in Zootaxa 5195 (3) on page 219, DOI: 10.11646/zootaxa.5195.3.1, http://zenodo.org/record/7187776

Culeolus suhmi Herdman, 1881 Figure 5 Culeolus suhmi Herdman 1881: 86; Sanamyan K. & Sanamyan N. 2002: 350, fig. 28, and synonymy; Sanamyan K. & Sanamyan N. 2005: 2015, fig. 8; Sanamyan K. & Sanamyan N. 2006: 331, fig. 13. Not Culeolus suhmi Millar, 1970: 136 (= Culeolus anonymus). Material examined: 63��34���S, 50��41���W, station 13, 2610 m, 14 March 2005, five specimens. Description. All specimens have the same external appearance and size (Fig. 5A). On average, they measure 5.5 cm wide and 3.5 cm long. The tunic is dull brown, completely covered by small vesicles. The atrial aperture is completely surrounded by a circular crest of crowded papillae forming a wide band made up of two to three rows. The papillae forming the crest are also covered by vesicles, as the rest of the tunic (Fig. 5B). Three of the samples have an extension of the crest running along the whole mid-ventral side of the body. The remaining two samples have this extension interrupted a very short distance from the crest. There are approximately 25 wide oral tentacles with ramifications of first and second orders and of two different sizes. These are distributed interspaced in a circle. The oral velum has a smooth border. The pre-pharyngeal band is double and circular, with slight undulations. The dorsal tubercle has a ���C��� shape. The dorsal lamina consists of a series of triangular languets that extends from the base of the dorsal tubercle to almost the entrance of the esophagus. The mantle is thin and delicate, but the musculature is thick. Transversal and longitudinal muscle fibers form a gridded network that covers the totality of the body. The branchial sac has no stigmata. It consists of a mesh of longitudinal and transverse vessels. The branchial formula for the largest specimen is: E - 2 (8) 6 (10) 6 (12) 7 (15) 7 (12) 6 (11) 4 - DL DL - 4 (13) 5 (11) 6 (12) 10 (11) 8 (9) 4 (9) 4 - E The gut forms an open loop. The esophagus is short. The stomach is completely covered by hepatic diverticula. The border of the anus has multiple and small lobes. Except for one damaged specimen, there are two gonads on the left side and two gonads on the right side (Fig. 5C). The number of gonadal lobes varies between one and eight: the first specimen (3.5 cm long and 5.5 cm wide) has four lobes in the posterior left gonad, eight lobes in the anterior left gonad, three lobes in the posterior right gonad, and six lobes in the anterior right gonad; the second specimen (3.5 cm long and 7 cm wide) has five lobes in the posterior left gonad, seven lobes in the anterior left gonad, three lobes in the posterior right gonad, and seven lobes in the anterior right gonad; the third specimen (2.5 cm long and 5 cm wide) has four lobes in the posterior left gonad, five lobes in the anterior left gonad, three lobes in the posterior right gonad, and five lobes in the anterior right gonad; the fourth specimen (4 cm long and 6 cm wide) has four lobes in the posterior left gonad, five lobes in the anterior left gonad, three lobes in the posterior right gonad, and five lobes in the anterior right gonad; the fifth specimen (damaged; 1.8 cm long and 3 cm wide) has only one gonad on the left side inside the gut loop with six lobes, while both right gonads have one lobe each. The position of the gonads in relation to the gut-loop is constant in all the specimens. On the left side, both gonads have the same length as the descending limb of the gut-loop. On the right side, the gonads run parallel to the endostyle and to each other. The posterior gonad, closer to the endostyle, is shorter than the anterior (Fig. 5C). Adhered to the peduncle and to the ventral side of the body of two adult specimens, we found two solitary ascidians that could not be identified due to their early stage of development (Fig. 5A). They measure 1 cm wide by 1 cm long and 2 cm wide by 2 cm long and have an ovoid shape. The tunic that surrounds them is thin and transparent, with thin and numerous projections. Stomach contents. In the stomach of three specimens we found pellet-shaped material (fecal pellets). In addition, in one of these we also found a complete amphipod (undetermined). Remarks. This is the first record of Culeolus suhmi in the Southern Ocean. It is also the southern record and the only geographic location that is shared with C. anonymus. The genus Culeolus has a high intra-specific variability of characters frequently used for species identification (Monniot C. & Monniot F. 1976; Kott 2002; Sanamyan K. & Sanamyan N. 2002). These characters are the position and number of the gonads and the structure of the postero-ventral crest (Sanamyan K. & Sanamyan N. 2002). Monniot C. & Monniot F. (1976) used the position of the gonads in relation to each other and to the gut-loop and the border of the anus to establish differences between Culeolus suhmi and C. anonymus, a species cited for the SW Atlantic area. Based on new material and on revisions of previously identified material, Sanamyan K. & Sanamyan N. (2002) doubted the value of these characters for delimitation of the discussed species because they were highly variable. They concluded that the only character stable enough to distinguish between C. anonymus and Culeolus suhmi is the shape of the crest. The number of gonads is variable in some species of the genus Culeolus, like in Culeolus suhmi (Sanamyan K. & Sanamyan N. 2005). After the study of new material the authors concluded that, even though in the majority of specimens the number of gonads on the right side is two, it could also ascend to three. Previously, Sanamyan K. & Sanamyan N. (2002) had suggested that this could be the product of an abnormality. In regard to the ascidian epibionts found, we could only detect a rudimentary endostyle and digestive tract, with no signs of branchial sac, gonads or muscular tissue. Unfortunately, due to the condition of these specimens no more details could be provided. The presence of ascidians in an early state of development attached to the bodies of adult conspecific specimens has been associated with gregarious behaviours in shallow water environments (Manr��quez & Castilla 2007; Castilla et al. 2007). In addition, some studies of associations among interspecific ascidians pointed to predation as the selective force maintaining the association (Young 1989; Davis 1996). Ascidian-ascidian associations, however, are not an exclusive attribute of shallow water environments. Although to a lesser extent, deep-sea ascidians have also been observed as basibionts and epibionts of other ascidians, including specimens of the genus Culeolus (Monniot C. & Monniot F. 1982; Sanamyan K. & Sanamyan N. 2002). Notwithstanding, the causes of this phenomenon at deeper depths still remain uncertain (Maggioni et al. in prep.)., Published as part of Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gast��n, Calcagno, Emilia & Tati��n, Marcos, 2022, Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications, pp. 296-314 in Zootaxa 5093 (3) on pages 303-304, DOI: 10.11646/zootaxa.5093.3.2, http://zenodo.org/record/5909824, {"references":["Herdman, W. A. (1881) Preliminary report on the Tunicata of the \" Challenger \" expedition. Part III. Cynthidae. Proceedings of the Royal society of Edinburgh, 11 (3), 52 - 58. https: // doi. org / 10.1017 / S 0370164600046782","Millar, R. H. (1970) Ascidians, including specimens from the deep-sea, collected by the R. V. ' Vema' and now in the American Museum of Natural History. Zoological Journal of the Linnean Society, 49 (2), 99 - 159. https: // doi. org / 10.1111 / j. 1096 - 3642.1970. tb 00732. x","Kott, P. (2002) Culeolus herdmani Sluiter, 1904 (Tunicata, Ascidiacea) from the northwestern Australian continental slope with an overview of the genus. Records of the Western Australian Museum, 21, 62 - 70. https: // doi. org / 10.18195 / issn. 0312 - 3162.21 (1). 2002.063 - 070","Manriquez, P. H. & Castilla, J. C. (2007) Roles of larval behaviour and microhabitat traits in determining spatial aggregations in the ascidian Pyura chilensis. Marine Ecology Progress Series, 332, 155 - 165. https: // doi. org / 10.3354 / meps 332155","Castilla, J. C., Manriquez, G. H., Delgado, A. P., Gargallo, L., Leiva, A. & Radic, D. (2007) Bio-foam enhances larval retention in a free-spawning marine tunicate. Proceedings of the National Academy of Sciences, 104 (46), 18120 - 18122. https: // doi. org / 10.1073 / pnas. 0708233104","Young, C. M. (1989) Selection of predator-free settlement sites by larval ascidians. Ophelia, 30 (2), 131 - 140. https: // doi. org / 10.1080 / 00785326.1989.10430840","Davis, A. R. (1996) Association among ascidians: facilitation of recruitment in Pyura spinifera. Marine Biology, 126, 35 - 41. https: // doi. org / 10.1007 / BF 00571375"]}

Culeolus likae Sanamyan K. & Sanamyan N., 2002 Figure 7 Culeolus likae Sanamyan K. & Sanamyan N. 2002: 347, fig. 26-27. Material examined: 70��40���S, 14��43���W, station 7, 3000 m, 22 Feb 2005, one specimen; 68��32���S, 20��24���W, station 9, 4930 m, 27 Feb 2005, one specimen. Description. Both specimens have a similar external aspect (Fig. 7A). The smaller specimen is 4 cm long and 1.7 cm wide, while its peduncle reaches 15 cm in length. The larger specimen is 10.9 cm long and 5.2 cm wide, while its peduncle reaches 187 cm in length. The tunic is white, almost transparent, through which body muscles can be seen. After formalin preservation it turns yellowish. It has a smooth appearance, although it is completely covered by tiny vesicles with pointy tips arranged somewhat away from each other (Fig. 7B). The postero-ventral crest is T-shaped: it consists of 3 continuous lamellae that end halfway along the body. The two lamellae that encircle the atrial aperture are interrupted at the dorsal region, failing to form a complete circle. The remaining third lamella runs through the mid-ventral line of the body. The oral siphon is situated at a short distance from the peduncle. The atrial siphon, situated posteriorly, is large. In the bigger specimen it measures 2 cm in diameter. A total of 34 oral tentacles of three different sizes are disposed in a circle. They have ramifications of three orders. The oral tentacle located over the dorsal region is the biggest. The pre-pharyngeal band is at a short distance from the oral aperture. It is composed of two smooth lamellae and makes a marked V around a prominent ���C���-shaped dorsal tubercle. The dorsal lamina, composed of separate triangular languets, extends from the border of the dorsal tubercle until the entrance of the esophagus. In the biggest specimen, we counted 55 languets. Strong longitudinal muscle fibers intercalate with strong transverse muscle fibers, forming a mesh. Thinner circular fibers are disposed around both siphons. There are six folds on each side of the branchial sac. The branchial formula for the left side of the biggest specimen is: DL -7 (10) 6 (10) 8 (6) 10 (7) 7 (5) 5 (5) 8- E The gut makes an open loop. The stomach is covered by two rows of hepatic diverticula. There is a wide atrial velum, with curved borders. The anal boder is smooth. Each gonad consists of a compact globular mass composed of numerous testicular follicles distributed over a short ovary. Both structures are embedded in a big endocarp. The gonads do not present lobes. There are three gonads on each side of the body. On the left side, the most ventral gonad is small and located in the gut-loop. The remaining two are located almost parallel to the intestine. On the right side, two gonads run almost parallel to the endostyle, one under the other. The remaining gonad, bigger in size, is located dorsally (Fig. 7C). Stomach contents. No remains of prey items were found. Remarks. This is the third record of Culeolus likae, increasing to seven the total number of specimens recorded. The geographic and bathymetric ranges of the species are extended, being the present the southern and shallowest register. The smaller specimen studied lacks part of the branchial sac, digestive system and gonads. Only the musculature, neural system, oral tentacles and dorsal lamina are intact. Notwithstanding, the external aspect is identical to the description for the species provided by Sanamyan K. & Sanamyan N. (2002). The larger specimen presents a peduncle which is 1 m longer than the longitude reported by the latter authors for the biggest specimen they collected (the holotype). Even though the position and the structure of the gonads may vary in some species of Culeolus, our intact specimen has the same position and shape of the one provided by Sanamyan K. & Samanyan N. (2002) for the holotype of C. likae. The differences found are: a higher number of oral tentacles (34 in our specimen; 20 in the holotype), the shape of the dorsal tubercle (���S���-shaped instead of ���C���-shaped) and the border of the anus (with two lobes instead of smooth). The difference in the number of oral tentacles could be due to the difference in size of the individuals compared. The shape of the dorsal tubercle is variable in numerous ascidian species; thus, we do not consider it a reliable character in the case of species diagnosis. The difference in the border of the anus might be attributed to incomplete fixation., Published as part of Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gast��n, Calcagno, Emilia & Tati��n, Marcos, 2022, Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications, pp. 296-314 in Zootaxa 5093 (3) on pages 307-308, DOI: 10.11646/zootaxa.5093.3.2, http://zenodo.org/record/5909824

Culeolus anonymus Monniot C. & Monniot F., 1976 Figure 6 Culeolus anonymus Monniot C. & Monniot F. 1976; Sanamyan K. & Sanamyan N. 2002: 344, fig 25, and synonymy. Culeolus suhmi: Millar, 1959: 199, figs. 11B and 11F (part: stations 663 y 668); Millar, 1970: 136, fig. 28. ? Culeolus wivylle-thomsoni Herdman, 1881 Material examined: 68��32���S, 20��34���W, station 9, 4930 m, 27 Feb 2005, one specimen. Description. The only specimen collected was found attached to the peduncle of Culeolus suhmi. Its body measures 1.8 cm long and 2.7 cm wide while the length of the peduncle reaches 6.5 cm, the shortest measure reported so far. The tunic is white (Fig. 6A). It is completely covered by tiny rounded-tipped vesicles, which give the surface of the animal a granulated aspect (Fig. 6B). The atrial aperture is surrounded by a crest of papillae interrupted dorsally. In the ventral region, the papillae of the crest are thicker and attached by their sides, creating a sort of stout lamella. There are no papillae in the mid-ventral region nor in any other region of the body (Figs. 6A, B). There are 32 oral tentacles, with ramifications of the one order, disposed in a circle. Bigger tentacles with wide bases are distributed interspaced with smaller and thinner tentacles. Some of the bases of the bigger tentacles are so wide that they extend beyond the line of insertion towards the oral aperture. There is no oral velum. The dorsal tubercle has a ���C��� shape. The pre-pharyngeal band is simple. It makes a pronounced V around the dorsal tubercle. The dorsal lamina is composed of 20 triangular languets. Strong muscle fibers form a gridded network over the mantle. The branchial sac has six folds on each side. The branchial formula for the left side is: DL - 2 (7) 2 (6) 3 (9) 3 (7) 3 (6) 2 (4) 4 - E There is a short esophagus that connects with a small stomach, which is covered by two rows of hepatic diverticula. The intestine is long and thick. The border of the anus has multiple lobes. A short atrial velum was observed. There are two gonads on each side of the body. On the left side, the posterior gonad is located inside the gut-loop, while the anterior gonad is located antero-dorsal to the gut-loop. Both right gonads are located parallel to the endostyle, in one line, one after another. The anterior gonads on both sides of the body have two lobes, while the ventral gonads have only one (Fig. 6C). Stomach contents. In the stomach of this specimen we found pellet-shaped material (fecal pellets). Remarks. Millar (1959) was the first who recognized two different species based on the morphologies of the postero-ventral crests of several specimens of Culeolus, which he temporarily identified as Culeolus suhmi. After the study of new material, Monniot C. & Monniot F. (1976) identified all specimens with postero-ventral crests interrupted dorsally as Culeolus anonymus. The authors originally described two populations based on the shape of the crest: one group with a continuous crest and the other with a crest composed of separate papillae. However, subsequent samples showed the existence of intermediate forms (Monniot C. & Monniot F. 1982). The number of branchial folds may also vary in C. anonymus. Although the most frequent is six folds per side, Sanamyan K. & Sanamyan N. (1999) observed five folds in specimens collected in the Indo-Pacific. Other species of Culeolus recorded in the Southern Ocean are: Culeolus antarcticus Vinogradova, 1962; Culeolus likae Sanamyan K. & Sanamyan N., 2002; Culeolus pinguis Monniot C. & Monniot F., 1982; and Culeolus recumbens Herdman, 1881. Culeolus anonymus is clearly distinguished from C. antarcticus and C. likae by the shape of the postero-ventral crest and by the number of gonads. The crest of both, C. antarcticus and C. likae, consists of a lamella that completely surrounds the atrial aperture and is interrupted dorsally, and extends along the mid-ventral side of the body. Moreover, C. antarcticus has one gonad consisting of one lobe on each side of the body, while C. likae presents three gonads per side. Culeolus pinguis presents a postero-ventral crest that surrounds the atrial aperture and two gonads with two lobes on each side. Finally, C. recumbens does not present gonads outside the gut-loop, and the postero-ventral crest completely surrounds the atrial aperture. In a revision of the genus, Kott (2002) proposed the synonymy between C. anonymus and Culeolus suhmi. This statement, although possible, is difficult to maintain based on the present available data. As such, the position and morphology of the gonads of the present specimen of C. anonymus is almost identical to the figure presented by Monniot C. & Monniot F. (1973) for specimens of Culeolus suhmi from the North Atlantic. However, the gonads of C. anonymus and Culeolus suhmi are extremely variable and, in some cases, almost identical. Although the only robust feature to differentiate between Culeolus suhmi and C. anonymus is the configuration of the postero-ventral crest (Sanamyan K. & Sanamyan N. 2002), the finding of two species in the Weddell Sea, one with internal characters more frequently found in the other, could be indicating that these species are, in fact, conspecific. However, until more material is available and completed with molecular studies, we propose to maintain C. anonymus and C. suhmi as separate species. In the most recent revision of the genus, Sanamyan et al. (2018) suggested that C. wivylle-thomsoni and C. anonymus could be conspecific based on a commentary by Monniot C. & Monniot F. (1982). According to the latter authors, the type specimen of C. wivylle-thomsoni could be an abnormal specimen of C. anonymus. Culeolus wivylle-thomsoni has not been collected since its original finding (see Herdman, 1881)., Published as part of Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gast��n, Calcagno, Emilia & Tati��n, Marcos, 2022, Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications, pp. 296-314 in Zootaxa 5093 (3) on pages 305-307, DOI: 10.11646/zootaxa.5093.3.2, http://zenodo.org/record/5909824, {"references":["Millar, R. H. (1959) Ascidiacea. Galathea Report, 1, 189 - 209.","Millar, R. H. (1970) Ascidians, including specimens from the deep-sea, collected by the R. V. ' Vema' and now in the American Museum of Natural History. Zoological Journal of the Linnean Society, 49 (2), 99 - 159. https: // doi. org / 10.1111 / j. 1096 - 3642.1970. tb 00732. x","Herdman, W. A. (1881) Preliminary report on the Tunicata of the \" Challenger \" expedition. Part III. Cynthidae. Proceedings of the Royal society of Edinburgh, 11 (3), 52 - 58. https: // doi. org / 10.1017 / S 0370164600046782","Vinogradova, N. (1962) Ascidiae simplices of the Indian part of the Antarctic. Biological results of the Soviet Antarctic expedition (1955 - 1958). Exploration of the faunas of the Seas I, 9, 196 - 215.","Kott, P. (2002) Culeolus herdmani Sluiter, 1904 (Tunicata, Ascidiacea) from the northwestern Australian continental slope with an overview of the genus. Records of the Western Australian Museum, 21, 62 - 70. https: // doi. org / 10.18195 / issn. 0312 - 3162.21 (1). 2002.063 - 070","Sanamyan, K., Sanamyan, N. & Kuhnz, L. (2018) A new Culeolus species (Ascidiacea) from the NE Pacific, California. Zootaxa, 4420 (2), 270 - 278. https: // doi. org / 10.11646 / zootaxa. 4420.2.8"]}

Detailed discussion of the nomenclatural history of the Pyuridae, Bolteniidae and related families is provided. It is shown that the valid nomen for the family currently known as Pyuridae is Bolteniidae. The generic nomen "Claudenus Kott, 1998" is not available and Claudenus is re-established here as intentionally new nomen (Claudenus Sanamyan & Sanamyan gen. nov.) The generic nomen Cratostigma is not available but no replacement nomen is suggested because we suppose that this genus may be congeneric with Bolteniopsis. The generic nomen Eupera Michaelsen, 1904 is invalid being a junior homonym, but a new replacement nomen is not suggested because it is synonymized here with Culeolus.

Tunicata is an interesting phylogenetic group, at the base of the branch leading to Chordata. Ascidians (Tunicata, Ascidiacea) morula blood cells are involved in defense reactions and in the formation of the tunic extracellular matrix. The ascidian tunic is hardened as a result of sclerotization of matrix proteins due to the action of phenol oxidase enzyme, contained in morula cells. Morula cells of the ascidian Styela rustica contain two major proteins, the function of which is still unknown; one of them is a protein with molecular mass of 48 kDa – p48. The aim of present study was to search for possible homologues of p48 in ascidians belonging to the Stolidobranchia order: Styela coriacea (Styelidae), Molgula citrina (Molgulidae), Boltenia echinata, Halocynthia aurantium (Pyuridae) and to determine the tissue distribution of those homologues. In order to show the presence of p48 in the tissues of sea squirts we used indirect immunolabeling method on paraffin sections.It was shown that the antibodies bind with morula cells of Styela rustica, Styela coreacea, Boltenia echinata, with the tunic matrix in all studied species and with test cells of Styela rustica, Styela coreacea, Boltenia echinata, Molgula citrina. It gives us a ground to assume the existence of p48 homologues in all studied ascidians and to expect a common mechanism of their participation in the tunic formation, as possible substrates of the phenol oxidase system.

Microcosmus longicloa Monniot C. & Monniot F., 1991 Figure 13 Stations: Kanacono DW 4727; DW 4728; DW 4781. Four specimens. The bodies of the different specimens in this collection all have the same shape (Fig. 13A). The largest specimen is 7 cm in length. The siphons are well apart, the atrial one always longer (Fig. 13). The tunic is rough and leathery but thin with spinules of 10µ on the siphonal lining (Fig. 12D). The muscle ribbons are evenly spaced and dense in a web on the body wall (Fig. 13C). There are about 60 thick ramified oral tentacles. The dorsal tubercle, C-shaped with horns rolled inward is placed in a deep V of the prepharyngeal band (Fig. 13B). The dorsal lamina has a plain edge. There are seven high folds on each side (Fig. 13B) and four to five longitudinal vessels between the folds. The digestive loop is ventral and only occupies a part of the left body side close to the endostyle (Fig. 13C). The digestive gland is in two parts: one anterior with lobes in lamellae and one posterior with thin finger-like papillae. The anus with eight lobes opens close to the oesophagus. There is one long gonad on each side. The left gonad crosses and covers the intestine the right gonad is also ventral (Fig. 13C). In all specimens two endocarps are placed anterior to the gonad on the right body side and one endocarp is above the gonad on the left body side, while additional endocarps cover the gonad lobes (Fig. 13C). There is an atrial velum but no papillae at the atrial aperture. The newly collected specimens are similar in all characters to those described from the same region (Monniot & Monniot 1991)., Published as part of Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, pp. 443-468 in Zootaxa 4996 (3) on pages 456-457, DOI: 10.11646/zootaxa.4996.3.2, http://zenodo.org/record/5074595, {"references":["Monniot, C. & Monniot, F. (1991) Tunicata: peuplements d'ascidies profondes en Nouvelle Caledonie. Diversite des strategies adaptatives. Memoires du Museum National d'Histoire Naturelle Paris, A, 151, 357 - 448."]}

Culeolus recumbens Herdman 1882 Figure 20 Stations: Kanadeep CP 5062; cp 5087; cp 5092; cp 5093. Eight specimens. Culeolus recumbens Herdman 1882: South West Indian Ocean; Monniot & Monniot 1982: Antarctic; Monniot & Monniot 199: New Caledonia; Monniot & López-Legentil 2017: Papua New Guinea; Sanamyan & Sanamyan 1999: North New Zealand. All specimens have the same shape with a triangular body held on a long stiff peduncle ending in a tuft of filaments (Fig. 20A). They are different sizes; the largest has a 3cm head and a peduncle 15cm long. The tunic is thin and soft on the head, spotted with button-like papillae with some adhering sand. A half ring of larger papillae encircles ventrally the anterior part of the body at some distance from the atrial aperture. The peduncle is flexible but harder, totally encrusted inserted at the side of the oral aperture. The body wall is thin and transparent with well spaced muscular bundles extending from the siphons and crossing the body sides (Fig. 20B–D). All specimens are damaged with the branchial sac and often the gonads and gut ejected through the atrial siphon. The oral tentacles are particularly long overlapping within the oral aperture. The dorsal tubercle opens in a slit above an elongated neural ganglion. The prepharyngeal band curves in a deep dorsal V. The dorsal lamina has large flat languets. It is difficult to determine if the branchial longitudinal vessels form three or four low folds on each side; in a specimen a tentative formula on the left side is: DL – 1 (4) 2 (4) 3 (3) 6 E The digestive loop is long and opened (Fig. 20B, C). The narrow stomach is covered by a digestive gland divided into several papillated lobes. The anus has numerous lobes. The gonads (Fig. 20B–D). are variable in number on each side according to the specimens, they can be from three to nine on the right side and from four to six on the left inside the gut loop. Their shape is uncommon for the genus they are similar to polycarps of the genus Polycarpa: testis and ovary are joined in a round gland with short joined ducts (Fig. 20B, C). One large endocarp is located on the body wall anterior to the gonads and another endocarp lies at the top of the intestine loop. No other endocarps were found. No spicules where seen in the tissues. Culeolus recumbens differs from other species of Culeolus present in New Caledonia by having several gonads on each side in the shape of polycarps. The external body shape may lead to confusion with other sandy pedunculate species of the same region., Published as part of Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, pp. 443-468 in Zootaxa 4996 (3) on pages 464-465, DOI: 10.11646/zootaxa.4996.3.2, http://zenodo.org/record/5074595, {"references":["Herdman, W. B. (1882) Report on the Tunicata collected during the Voyage of H. M. S. Challenger during the years 1873 - 1876. Part 1. Ascidiae simplices. Report on the Scientific results of the Voyage of H. M. S. Challenger, Zoology, VI, 1 - 285.","Monniot, C. & Monniot, F. (1982) Some Antarctic deep-sea tunicates in the Smithsonian collections. In: Biology of the Antarctic seas. 10. Antarctic Research Series, 32, pp. 95 - 130. https: // doi. org / 10.1029 / AR 032 p 0095","Monniot, F. & Lopez-Legentil, S. (2017) Deep-Sea ascidians from Papua New Guinea. Zootaxa, 4276 (4), 529 - 538. https: // doi. org / 10.11646 / zootaxa. 4276.4.5","Sanamyan, K. E. & Sanamyan, N. P. (1999) Some benthic Tunicata from the southern Indo-Pacific Ocean. Journal of Natural history, 33, 1835 - 1876. https: // doi. org / 10.1080 / 002229399299761"]}

Herdmania sp. All tiny juveniles less than 1 cm. #1214; #1230A, three; #3728C; #3827E, on Polycarpa argentata., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842

Microcosmus sp. #4651, tiny; reddish tunic. Size fully relaxed 1.2 cm in length, 0.8 cm wide at base of red-striped siphons. Gonad not well developed., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842

Unidentified Pyuridae #3858A, small individual, 1 cm across out of tunic. Tunic covered with very long slender tunic spines/tubercles. Siphons striped red and white., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 31, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842

During the 2013 Singapore Strait International Marine Biodiversity Workshop, hundreds of ascidians were collected along with numerous other marine phyla. Collections were made intertidally as well as subtidally by snorkel, SCUBA, trawling and dredging. While many ascidian specimens remain unidentified, 14 aplousobranchs, nine phlebobranchs and 17 stolidobranchs have been identified; a surprising 50% of these comprise 20 new records for Singapore. An additional new record of the phlebobranch Perophora namei collected from the same area in 2014 and 2015 is included here. Of the 21 new records, Aplidium cf. grisiatum, Distaplia regina, Euherdmania cf. digitata, Cnemidocarpa irene, Monandrocarpa monotestis and Polyandrocarpa rollandi are also first records for the entire South China Sea region.

Pyura curvigona Tokioka, 1950 Figures 11E, F #2655B, small specimen embedded in Polyandrocarpa rollandi colony (#2655A); body in tunic 2 cm tall, 2.2 cm wide. Long iridescent siphonal spines up to about 211 ��m. Rectum swollen, anus with many rounded lobes. Liver greenish, dark. Amphipod in branchial sac. Widely distributed in tropical western Pacific: China, Hong Kong, Indonesia, Singapore, Vietnam, Australia, Palau, Truk, Majuro, Japan, Okinawa, Guam. Detailed references with illustrations: Tokioka (1950, 1967), Millar (1975), Kott & Goodbody (1982), Kott (1985), Cole & Vorontsova (1998), Monniot F. (2009b), Lee et al. (2013). Other references: Tokioka & Nishikawa (1975), Nishikawa (1984), Kott (1992), Zheng (1995), Lambert (2003), Lee et al. (2016)., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 31, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842, {"references":["Tokioka, T. (1950) Ascidians from the Palao Islands. Publications of the Seto Marine Biological Laboratory, 1, 115 - 150. https: // doi. org / 10.5134 / 174438","Tokioka, T. (1967) Pacific Tunicata of the United States National Museum. Bulletin of the United States National Museum, 251, 1 - 247. https: // doi. org / 10.5479 / si. 03629236.251.1","Millar, R. H. (1975) Ascidians from the Indo-West-Pacific region in the Zoological Museum, Copenhagen (Tunicata, Ascidiacea). Steenstrupia, 3, 205 - 336.","Kott, P. & Goodbody, I. (1982) The ascidians of Hong Kong. In: Morton, B. S. & Tseng, C. K. (Eds.), Proceedings of the First International Marine Biological Workshop: The Marine Flora and Fauna of Hong Kong and Southern China, Hong Kong, 1980. University Press, Hong Kong, pp. 503 - 554.","Kott, P. (1985) The Australian Ascidiacea part 1, Phlebobranchia and Stolidobranchia. Memoirs of the Queensland Museum, 23, 1 - 440.","Cole, L. & Vorontsova, M. (1998) Species of Pyuridae (Ascidiacea) from South Vietnam. Bulletin of Marine Science, 62, 1 - 6.","Lee, S. S. - C., Teo, S. L. - M. & Lambert, G. (2013) New records of solitary ascidians on artificial structures in Singapore waters. Marine Biodiversity Records, 6, 1 - 18. https: // doi. org / 10.1017 / S 1755267213000638","Tokioka, T., & Nishikawa, T. (1975) Contribution to the Japanese ascidian fauna. 27. Some ascidians from Okinawa, with notes on a small collection from Hong Kong. Publications of the Seto Marine Biological Laboratory, 22, 323 - 341. https: // doi. org / 10.5134 / 175896","Nishikawa, T. (1984) Ascidians from the Truk Islands, Ponape Island and Majuro Atoll (Tunicata, Ascidiacea). Proceedings of the Japanese Society of Systematic Zoology, 27, 107 - 140.","Kott, P. (1992) The Australian Ascidiacea part 3, Aplousobranchia (2) and Supplement 2. Memoirs of the Queensland Museum, 32, 375 - 655.","Zheng, C. (1995) Species diversity of ascidian in the coastal China Seas. Chinese Biodiversity, 3 (4), 201 - 205.","Lambert, G. (2003) Marine biodiversity of Guam: the Ascidiacea. Micronesica, 35 - 36, 588 - 597.","Lee, S. S. - C., Chan, J. Y-H., Teo, S. L. - M. & Lambert, G. (2016) State of knowledge of ascidian diversity in South China Sea and new records for Singapore. Raffles Bulletin of Zoology, Supplement 34, 718 - 743."]}

Herdmania pallida (Heller, 1878) #0154E, one small, on floating pontoon; #2641A, one; #3801, one large; #4615, one small; Cyrene patch reef, one not collected. Wide distribution in tropical west Pacific: Hong Kong, Indonesia, Philippines, Japan, Singapore, Palau, New Caledonia, Guam, Hawaii. Introduced in the Atlantic: SE U.S., Caribbean, Martinique, Brazil. Detailed references with illustrations: Monniot F. & Monniot C. (2001), Kott (2002b), Monniot C. (2002), Nishikawa (2002 part), Lee et al. (2013), Monniot F. & Debitus (2015), Monniot F. (2018c). Other references: Van Name (1918), Rocha & Costa (2005), Rocha et al. (2005), Lambert (2003), Lee et al. 2016)., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 27, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842, {"references":["Heller, C. (1878) Beitrage zur nahern Kenntniss der Tunicaten. Sitzungsberichte der Akademie der Wissenschaften in Wien, 77 (1), 83 - 110.","Kott, P. (2002 b) The genus Herdmania Lahille, 1888 (Tunicata, Ascidiacea) in Australian waters. Zoological Journal of the Linnean Society, 134, 359 - 374. https: // doi. org / 10.1046 / j. 1096 - 3642.2002.00009. x","Nishikawa, T. (2002) Revision of the ascidian genus Herdmania (Urochordata: Ascidiacea) inhabiting Japanese waters. Species Diversity, 7, 217 - 250. https: // doi. org / 10.12782 / specdiv. 7.217","Lee, S. S. - C., Teo, S. L. - M. & Lambert, G. (2013) New records of solitary ascidians on artificial structures in Singapore waters. Marine Biodiversity Records, 6, 1 - 18. https: // doi. org / 10.1017 / S 1755267213000638","Van Name, W. G. (1918) Ascidians from the Philippines and adjacent waters. Bulletin of the United States National Museum, 100, 49 - 174.","Rocha, R. M. & Costa, L. V. G. (2005) Ascidians (Urochordata: Ascidiacea) from Arraial do Cabo, Rio de Janeiro, Brazil. Iheringia, Serie Zoologia, 95, 57 - 64. https: // doi. org / 10.1590 / S 0073 - 47212005000100009","Lambert, G. (2003) Marine biodiversity of Guam: the Ascidiacea. Micronesica, 35 - 36, 588 - 597.","Lee, S. S. - C., Chan, J. Y-H., Teo, S. L. - M. & Lambert, G. (2016) State of knowledge of ascidian diversity in South China Sea and new records for Singapore. Raffles Bulletin of Zoology, Supplement 34, 718 - 743."]}

Microcosmus exasperatus Heller, 1878 Figure 11A, B Individuals may reach 5 cm across, usually somewhat wider than tall, with a thick ridge of tunic between the widely spaced siphons especially when contracted. Siphonal spines small, dense, curved and sharply pointed, usually up to about 30 ��m in length but may be slightly longer in large specimens. Tunic lining purple, siphonal lining red striped and mottled. Dorsal tubercle inrolled. Gonad in three parts on each side, left gonad crosses gut. #0154A, nine branchial folds per side. One gammarid amphipod in branchial sac. #3799C, juvenile 1.7 cm long. Creamy white tunic with red striping; resembles Polycarpa papillata externally. Oral siphon terminal, atrial siphon far back; siphons with red striping. Gonads not well developed but in the typical three parts. #3827D, one small, on Polycarpa argentata. #4614, small; 1.2 cm anteroposteriorly. Siphonal spines up to 44 ��m long including embedded basal part. Eight branchial folds on the right side, seven on the left. Distribution: China, Formosa, Indonesia, Philippines, Singapore, Vietnam, Australia, Hawaii, Guam, Fiji, Truk, New Caledonia, French Polynesia, Gal��pagos, E. and W. Africa, Suez and eastern Mediterranean, SE. U.S., Caribbean, Martinique, Brazil. Detailed references: Van Name (1918 as Pyura exasperatus; 1945); Millar (1975), Kott (1981, 1985); Monniot C. & Monniot F. (1987), Cole & Vorontsova (1998), Monniot C. (2002), Monniot F. (2010, 2018c), Lee et al. (2013). Other references: Millar (1965), Monniot C. (1983c), Nishikawa (1984), Monniot C. et al. (1985), Millar (1988), Monniot C. & Monniot F. (1994), Zheng (1995), Abbott et al. (1997), Rocha & Nasser (1998), Rocha & Costa (2005), Rocha et al. (2005), Shenkar & Loya (2009), Lee et al. (2016), Lambert (2003, 2019)., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842, {"references":["Heller, C. (1878) Beitrage zur nahern Kenntniss der Tunicaten. Sitzungsberichte der Akademie der Wissenschaften in Wien, 77 (1), 83 - 110.","Van Name, W. G. (1918) Ascidians from the Philippines and adjacent waters. Bulletin of the United States National Museum, 100, 49 - 174.","Millar, R. H. (1975) Ascidians from the Indo-West-Pacific region in the Zoological Museum, Copenhagen (Tunicata, Ascidiacea). Steenstrupia, 3, 205 - 336.","Kott, P. (1981) The ascidians of the reef flats of Fiji. Proceedings of the Linnean Society of New South Wales, 105, 147 - 212.","Kott, P. (1985) The Australian Ascidiacea part 1, Phlebobranchia and Stolidobranchia. Memoirs of the Queensland Museum, 23, 1 - 440.","Cole, L. & Vorontsova, M. (1998) Species of Pyuridae (Ascidiacea) from South Vietnam. Bulletin of Marine Science, 62, 1 - 6.","Lee, S. S. - C., Teo, S. L. - M. & Lambert, G. (2013) New records of solitary ascidians on artificial structures in Singapore waters. Marine Biodiversity Records, 6, 1 - 18. https: // doi. org / 10.1017 / S 1755267213000638","Millar, R. H. (1965) Ascidians from the tropical coast of west Africa. Scientific Results of the Danish Expedition to the coasts of tropical west Africa 1945 - 1946. Atlantide Report, 8, 247 - 255.","Nishikawa, T. (1984) Ascidians from the Truk Islands, Ponape Island and Majuro Atoll (Tunicata, Ascidiacea). Proceedings of the Japanese Society of Systematic Zoology, 27, 107 - 140.","Millar, R. H. (1988) Ascidians collected during the International Indian Ocean Expedition. Journal of Natural History, 22, 823 - 848. https: // doi. org / 10.1080 / 00222938800770541","Zheng, C. (1995) Species diversity of ascidian in the coastal China Seas. Chinese Biodiversity, 3 (4), 201 - 205.","Abbott, D. P., Newberry, A. T. & Morris, K. M. (1997) Reef and Shore Fauna of Hawaii. 6 B: Ascidians (Urochordata). Bishop Museum Press, Honolulu, 64 pp.","Rocha, R. M. & Nasser, C. M. (1998) Some ascidians (Tunicata, Ascidiacea) from Parana State, southern Brazil. Revista Brasileira de Biologia, 15, 633 - 642. https: // doi. org / 10.1590 / S 0101 - 81751998000300009","Rocha, R. M. & Costa, L. V. G. (2005) Ascidians (Urochordata: Ascidiacea) from Arraial do Cabo, Rio de Janeiro, Brazil. Iheringia, Serie Zoologia, 95, 57 - 64. https: // doi. org / 10.1590 / S 0073 - 47212005000100009","Shenkar, N. & Loya, Y. (2009) Non-indigenous ascidians (Chordata: Tunicata) along the Mediterranean coast of Israel. Marine Biodiversity Records, 2, 1 - 7. https: // doi. org / 10.1017 / S 1755267209990753","Lee, S. S. - C., Chan, J. Y-H., Teo, S. L. - M. & Lambert, G. (2016) State of knowledge of ascidian diversity in South China Sea and new records for Singapore. Raffles Bulletin of Zoology, Supplement 34, 718 - 743.","Lambert, G. (2003) Marine biodiversity of Guam: the Ascidiacea. Micronesica, 35 - 36, 588 - 597.","Lambert, G. (2019) Fouling ascidians (Chordata: Ascidiacea) of the Galapagos: Santa Cruz and Baltra Islands. Aquatic Invasions, 14, 132 - 149. https: // doi. org / 10.3391 / ai. 2019.14.1.05"]}

Microcosmus helleri Herdman, 1881 Figure 11C, D Tunic lumpy, tough, tan to light brown in color, usually heavily fouled. Siphons widely separated and directed away from each other; no siphonal spines. Four large oral flaps at base of branchial siphon, six tall branchial folds per side. Liver composed of parallel lamellae with surface papillae. #1172, attached to Cnemidocarpa irene (specimen #1192). Small; 15 mm tall x 15 mm in width. Gonad in two sections on both sides, crosses gut on left side. #4654, small, 2 cm in width; body out of tunic 16 mm wide. Small mytilid bivalve embedded in anterior tunic between the siphon bases. Distribution: Australia, Guam, Indonesia, Sri Lanka, Malaysia, Singapore, E. Africa, Caribbean, Puerto Rico, Martinique, Brazil. Detailed references with illustrations: Van Name (1945), Kott (1985), Monniot F. (2018c).Additional references: Monniot C. & Monniot F. (1994), Lambert (2003), Rocha et al. (2012), Lee et al. (2016)., Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/4547842, {"references":["Herdman, W. A. (1881) Preliminary report on the Tunicata of the \" Challenger \" Expedition. Part III [Styelidae and Pyuridae]. Proceedings of the Royal Society of Edinburgh, 11, 52 - 88. https: // doi. org / 10.1017 / S 0370164600046782","Van Name, W. G. (1945) The North and South American ascidians. Bulletin of the American Museum of Natural History, 84, 1 - 476.","Kott, P. (1985) The Australian Ascidiacea part 1, Phlebobranchia and Stolidobranchia. Memoirs of the Queensland Museum, 23, 1 - 440.","Lambert, G. (2003) Marine biodiversity of Guam: the Ascidiacea. Micronesica, 35 - 36, 588 - 597.","Rocha, R. M., Zanata, T. B. & Moreno, T. R. (2012) Keys for the identification of families and genera of Atlantic shallow water ascidians. Biota Neotropica, 12, 1 - 35. https: // doi. org / 10.1590 / S 1676 - 06032012000100022","Lee, S. S. - C., Chan, J. Y-H., Teo, S. L. - M. & Lambert, G. (2016) State of knowledge of ascidian diversity in South China Sea and new records for Singapore. Raffles Bulletin of Zoology, Supplement 34, 718 - 743."]}

The transparency of animals is an important biological feature. Ascidian eggs have various degrees of transparency, but this characteristic has not yet been measured quantitatively and comprehensively. In this study, we established a method for evaluating the transparency of eggs to first characterize the transparency of ascidian eggs across different species and to infer a phylogenetic relationship among multiple taxa in the class Ascidiacea. We measured the transmittance of 199 eggs from 21 individuals using a hyperspectral camera. The spectrum of the visual range of wavelengths (400–760 nm) varied among individuals and we calculated each average transmittance of the visual range as bio-transparency. When combined with phylogenetic analysis based on the nuclear 18S rRNA and the mitochondrial cytochrome c oxidase subunit I gene sequences, the bio-transparencies of 13 species were derived from four different families: Ascidiidae, Cionidae, Pyuridae, and Styelidae. The bio-transparency varied 10–90% and likely evolved independently in each family. Ascidiella aspersa showed extremely high (88.0 ± 1.6%) bio-transparency in eggs that was maintained in the “invisible” larva. In addition, it was indicated that species of the Ascidiidae family may have a phylogenetic constraint of egg transparency.

Este artículo contiene 14 páginas, 2 tablas, 3 figuras., Background: Tunicates are the closest relatives of vertebrates and are widely used as models to study the evolutionary developmental biology of chordates. Their phylogeny, however, remains poorly understood, and to date, only the 18S rRNA nuclear gene and mitogenomes have been used to delineate the major groups of tunicates. To resolve their evolutionary relationships and provide a first estimate of their divergence times, we used a transcriptomic approach to build a phylogenomic dataset including all major tunicate lineages, consisting of 258 evolutionarily conserved orthologous genes from representative species. Results: Phylogenetic analyses using site-heterogeneous CAT mixture models of amino acid sequence evolution resulted in a strongly supported tree topology resolving the relationships among four major tunicate clades: (1) Appendicularia, (2) Thaliacea + Phlebobranchia + Aplousobranchia, (3) Molgulidae, and (4) Styelidae + Pyuridae. Notably, the morphologically derived Thaliacea are confirmed as the sister group of the clade uniting Phlebobranchia + Aplousobranchia within which the precise position of the model ascidian genus Ciona remains uncertain. Relaxed molecular clock analyses accommodating the accelerated evolutionary rate of tunicates reveal ancient diversification (~ 450–350 million years ago) among the major groups and allow one to compare their evolutionary age with respect to the major vertebrate model lineages. Conclusions: Our study represents the most comprehensive phylogenomic dataset for the main tunicate lineages. It offers a reference phylogenetic framework and first tentative timescale for tunicates, allowing a direct comparison with vertebrate model species in comparative genomics and evolutionary developmental biology studies., This work was supported by the Centre National de la Recherche Scientifique and the Agence Nationale de la Recherche (Contract ANR-13- BSV2–0011-01) to P.L and E.J.P.D. and by the Labex TULIP (ANR-10-LABX-41) to H.P. Computations were made on the Montpellier Biodiversity Bioinformatics (MBB) platform of the Labex CeMEB, and on the Mp2 and Ms2 supercomputers from the Université de Sherbrooke, managed by Calcul Québec and Compute Canada. The operation of this supercomputer is funded by the Canada Foundation for Innovation (CFI), the ministère de l’Économie, de la science et de l’innovation du Québec (MESI), and the Fonds de recherche du Québec - Nature et technologies (FRQ-NT).

Halocynthia aurantium (Stolidobranchia: Pyuridae) is a species of tunicate of commercial value that is commonly found in the northern Pacific Ocean and in the Bering Sea. Here, we determined the complete mitogenome of sea peach H. aurantium using 150 PE high-throughput sequencing. The assembled mitogenome is 14,979 bp in length (overall A + T contents 56.2%), and contains 13 protein-coding genes, 21 transfer RNAs, two ribosomal RNAs. Phylogenetic analysis of the mitogenome sequence of H. aurantium fully resolved it in a clade with H. roretzi. These data and results will be useful for future studies on the evolution of the Halocynthia and the Pyuridae.

Halocynthia hilgendorfi ritteri is an ascidian distributed on the coast of Geoje Island in Korea and found on rocks. The mitochondrial genome of Halocynthia hilgendorfi ritteri consists of 15,181 bp with 13 protein-coding genes, 2 ribosomal RNAs, 23 transfer RNA genes. The overall base composition of the complete genome is 22.94% A, 43.32% T, 25.72% G, and 8.02% C, with a high A + T content of 66.26%.

Boltenia villosa (Stimpson, 1864) Figure 12C IHAK 12 BHAK 0607, 0608 UF 2465. Three very small specimens, under rocks by lab, low intertidal. BHAK 0734 vouchered as tissue sample only. IHAK 18 BHAK 0640, 0641 UF 2491, 2492. Under lab dock. Three specimens, smallest one discarded. IHAK 52 A Mouth of Kwakshua, Scuba, 5 m. One small. MHAK 14 BHAK 0624 UF 2475. Tippy Rock Bay, low intertidal. Small. With M. taylori, P. annectens. Rarely over 3 cm in width, usually bright red, with widely separated siphons at the anterior end of the somewhat heart-shaped body, and a stalk of variable length which can be as much as four times the body length (O’Clair & O’Clair 1998). The tunic is always thickly covered with hairs of various lengths that may be minutely branched, resulting in the body often being covered with detritus and various epibionts. For detailed description see Huntsman (1912b) and Van Name (1945); other descriptions and distribution in Abbott & Newberry (1980), O’Clair & O’Clair (1998), and Lamb & Hanby (2005). Native to the NE Pacific coast from Alaska to southern California., Published as part of Lambert, Gretchen, 2019, The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz, pp. 401-436 in Zootaxa 4657 (3) on page 424, DOI: 10.11646/zootaxa.4657.3.1, http://zenodo.org/record/3371886, {"references":["Stimpson, W. (1864) Description of new species of marine Invertebrata from Puget Sound, collected by the naturalists of the North-west Boundary Commission. Proceedings of the Academy of Natural Sciences of Philadelphia, 16, 153 - 161. https: // doi. org / 10.5962 / bhl. title. 5972 0","O'Clair, R. M. & O'Clair, C. E. (1998) Southeast Alaska's Rocky Shores. Plant Press, Auke Bay, Alaska, 564 pp.","Huntsman, A. G. (1912 b) Holosomatous ascidians from the coast of western Canada. Contributions to Canadian Biology 1906 - 1910, 103 - 185. https: // doi. org / 10.1139 / f 06 - 010 b","Van Name, W. G. (1945) The North and South American ascidians. Bulletin of the American Museum of Natural History, 84, 1 - 476.","Abbott, D. P. & Newberry, A. T. (1980) Urochordata: the tunicates. In: Morris, R. H., Abbott, D. P. & Haderlie, E. C. (Eds.), Intertidal Invertebrates of California. Stanford, California, Stanford University Press, pp. 177 - 226 + P 57 - P 67.","Lamb, A. & Hanby, B. P. (2005) Marine Life of the Pacific Northwest - A Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes. Harbour Publishing, Madeira Park, BC., 398 pp."]}

Halocynthia aurantium (Pallas, 1787) Figure 12A IHAK 50 BHAK 1720 UF 2532. Hakai Passage, Port Reef, Scuba, 21 m. Vertical rock wall, fast current. Large: 10 cm long including siphons, 5.5 cm wide at base. IHAK 52 BHAK 1727 UF 2539. Mouth of Kwakshua, Scuba, 22 m. One small specimen, 4 cm in length. IHAK 55 BHAK 1737 UF 2548. Kwakshua Petroglyph Cliff, Scuba, 17–20 m, vertical rock wall, high current. One large specimen. IHAK 67 Under the Pruth Bay dock. Two small specimens. This is a large species, orange or reddish-orange in color, often up to 10 cm in length but 15 cm specimens have been recorded (Ritter 1900). Although both siphons are at the anterior end, the atrial siphon is somewhat recurved (Fig. 12A). The tunic is thickly covered with small rounded papillae with very short spines projecting from the top of each papilla. There are longer minutely branched spines around the siphons. It is closely related to the North Atlantic H. pyriformis (Rathke, 1806) but based on an extensive comparison of the two species by Ritter (1913), there are distinct differences such as number of gonads, pattern of tunic spines, and length/width ratio. Van Name (1945) summarized these differences. In the NE Pacific this species’ native range extends from Alaska to Washington (Huntsman 1912a, b; Van Name 1945; Lambert CC et al. 1996). It is also native in the NW Pacific and is extensively cultured for food in northern Japan, while wild specimens are collected for food in Korea and Russia (Lambert et al. 2016)., Published as part of Lambert, Gretchen, 2019, The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz, pp. 401-436 in Zootaxa 4657 (3) on page 424, DOI: 10.11646/zootaxa.4657.3.1, http://zenodo.org/record/3371886, {"references":["Ritter, W. E. (1900) Some ascidians from Puget Sound, collections of 1896. Annals of the New York Academy of Sciences, 12, 589 - 616. https: // doi. org / 10.1111 / j. 1749 - 6632.1899. tb 54995. x","Ritter, W. E. (1913) The simple ascidians from the northeastern Pacific in the collection of the United States National Museum. Proceedings of the U. S. National Museum, 45, 427 - 505. https: // doi. org / 10.5479 / si. 00963801.45 - 1989.42 7","Van Name, W. G. (1945) The North and South American ascidians. Bulletin of the American Museum of Natural History, 84, 1 - 476.","Huntsman, A. G. (1912 a) Ascidians from the coasts of Canada. Transactions of the Royal Canadian Institute, annals 1911, 9, 111 - 148. https: // doi. org / 10.5962 / bhl. part. 1313 6","Lambert, G., Karney, R. C., Rhee, W. Y. & Carman, M. R. (2016) Wild and cultured edible tunicates: a review. Management of Biological Invasions, 7, 59 - 66. https: // doi. org / 10.3391 / mbi. 2016.7.1.0 8"]}

A three-week intensive marine biodiversity survey was carried out at a small remote region of the central British Columbia coast at and near the Calvert Island Marine Station (Hakai Institute) July 21–August 11, 2017. The survey included daily sampling by the staff and a number of visiting taxonomists with specialties covering all the major groups of invertebrates. Many marine habitats were sampled: rocky and sand/gravel intertidal and tidepools, eelgrass meadows, shallow and deeper subtidal by snorkel and Scuba, plus artificial surfaces including the sides and bottom of the large floating dock at the Institute and settlement plates set out up to a year previously at various subtidal sites. Many new species were recorded by all the taxonomists. In this very biodiverse remote area 36 ascidian species were identified: 18 Aplousobranchia, 7 Phlebobranchia, and 11 Stolidobranchia, comprising a total of 15 solitary and 21 colonial species including two undescribed colonial species. This represents almost one third of all the known North American species from Alaska to southern California in this limited very remote area. Remarkably, only two are possible non-natives. Diplosoma listerianum (Milne-Edwards, 1841), was collected mostly on natural substrates including deeper areas sampled by Scuba, and one colony occurred on a settlement plate. A few Ciona savignyi Herdman, 1882 were collected, two from natural substrates and four from artificial surfaces. There were no botryllids, Styela clava Herdman, 1881, Didemnum vexillum Kott, 2002, or Molgula manhattensis (De Kay, 1843), though these are all common and sometimes very abundant non-natives in other parts of BC and along much of the U.S. west coast. Most of the species encountered are known in northern California, Washington, and southern BC, but only a small number are represented among the few known Alaska species.

Pyura lopezlegentilae sp. nov. (Figures 9���11) urn:lsid:zoobank.org:act: 006BDF9E-AC66-4805-BC18-49F0E1D21F6E Material examined: Holotype: MZUSP556 Crawl Key, Bocas del Toro, 9��14'38���N 82��08'25���W, leg. R. M. Rocha, 25.08.2006 Paratypes: DZUP PYU-87, Punta Caracol, Isla Colon, Bocas del Toro, 9��22���37.6���N 82��18���7���W, leg. R. Collin, 05.08.2003; DZUP PYU-88, Solarte, Bocas del Toro, 9��17'30���N 82��10'20���W, leg. R. M. Rocha, 11.08.2003; DZUP PYU-111, Bastimentos, Bocas del Toro, 9��16'37���N 82��10'16���W, leg. R. M. Rocha, 04.08.2008; DZUP PYU-112, STRI Bay, Bocas del Toro, 9��21'09���N 82��15'32���W, leg. R. M. Rocha, 27.08.2008, DZUP PYU- 113, Big Bight, Bocas del Toro, 9��21'56���N, 82��16'49���W, leg. R. M. Rocha, 06.06.2009; DZUP PYU-114, Garden Reef, Isla Solarte, Bocas del Toro, 9��19'23���N 82��13'11���W, leg. R. M. Rocha, 11.06.2009; DZUP PYU-115, City Pilings, Bocas del Toro, 9��20'27���N 82��14'21���W, 19.08.2006; DZUP PYU-116, Isla Solarte, Bocas del Toro, 9��17'55.74���N 82��11'40.32���W, leg. G. Lambert, 15.08.2006; DZUP PYU-117, Isla Colon-Mangrove, Bocas del Toro, 9��21'41.9���N 82��16'28.9���W, leg. R. M. Rocha, 25.07.2008; DZUP PYU-118, STRI Dock, Bocas del Toro, 9��21'41.9���N 82��16'28.9���W, leg. R. M. Rocha, 03.08.2006; DZUP PYU-119, Isla Pastores, Bocas del Toro, 9��13'09���N 82��19'29���W, leg. R. M. Rocha, 14.06.2011; DZUP PYU-120, Bastimentos, 9��16���31.8���N 82��10���16.9"W, leg. R. M. Rocha, 04.07.2011; DZUP PYU-121, Isla Colon, Bocas del Toro, 9��21'45.95���N 82��16'30.01���W, leg. R. M. Rocha, 02.07.2011; DZUP PYU-122, Punta Caracol, Bocas del Toro, 9��22'28���N 82��17'57���W, leg. R. M. Rocha, 24.06.2011; DZUP PYU-123, Almirante Bay, Bastimentos, Bocas del Toro, 9��14'33.72���N 82��08'57.84���W, leg. R. M. Rocha, 28.06.2011; DZUP PYU-124, Solarte, Bocas del Toro, 9��16'38.9���N 82��12'24.1���W, leg. R. M. Rocha, 19.06.2014; DZUP PYU-125, Mangrove, Solarte, Bocas del Toro, 9��18'36.3���N 82��12'23.04���W, leg. R. M. Rocha, 10.06.2011. Etymology. The name of the species is in homage to Susanna L��pez-Legentil for her important research contributions on ascidian genetics and systematics. Description. Living specimens inhabit piers, mangroves, and coral reefs. Animals are oval shaped and reach up to 4 cm. Fresh specimens frequently display red and yellow siphons; however, in some samples, the siphons show only red coloration (Fig. 9). A distinctive membrane, resembling a flap and often yellow in color, is viewed through the atrial siphon and is part of the vellum that line that siphon (Fig 9B, C). Epibionts cover the outside of the tunic. After fixation, the tunic displays yellow and brown and is 1���3 mm thick. The inside of the tunic is white. The holotype is 2.2 cm in height and 3.0 cm wide; brown in color when preserved. The siphons are extremely contracted from fixation. The tunic is rough with bumps densely concentrated around the siphons. Without the tunic, the holotype is 1.3 cm in height and 2.1 cm wide, discounting the siphons. Both the oral and atrial siphons are 4 mm long. The continuation of the tunic inside the siphons form an iridescent vellum, containing many short and parrot-beak-shaped spines (40���50 ��m) with a red spot in each (Fig. 10C). The body wall has no coloration; however, when fresh, the siphons are red. The red coloration dissipates the longer the length of fixation. A small round projection of the body wall is always viewed at the base of the oral siphon, on the ventral margin at the level of the anterior end of the endostyle (Fig. 10A). Dense circular muscles surround the siphons and extend a slight distance onto the body wall. Longitudinal muscles form muscle bands that radiate from the base of the siphons slowly disbanding toward the gonadal and intestinal region. The gonadal and intestinal region is transparent and the large, spherical gonad lobes are easily seen through the body wall (Figs 10A, B, D). The holotype contains 29 laterally flattened tentacles with three orders of sizes, the largest 3���4 mm long. The number of tentacles ranges from 29 to 40. Several specimens show a higher degree of ramification than others. There is little separation between the tentacles and the prepharyngeal groove; which is made up of two equal sized membranes. The shape of the dorsal tubercle varies among samples. In the holotype, the dorsal tubercle is a thick U-shape situated in a deep V constructed by the prepharyngeal groove. The ends can be coiled. In one sample, the dorsal tubercle was offset to the right of the neural ganglion and significantly smaller than the other samples (Fig 11B, C). The dorsal lamina begins a few millimeters posterior to the V-shaped peritubercle region. Long languets are densely placed down the entire length of the dorsal lamina; 150 in the holotype. The pharynx is uncolored with six high folds per side. Folds commonly being higher the closer to the dorsal lamina. Overlap of folds occurs; more prevalent on the left side (Fig. 11A). The holotype has a total of 369 longitudinal vessels; number of vessels range from 335 to 369. The longitudinal vessel formula of the holotype is (from right to left): E 4 (20) 4 (24) 6 (29) 3 (30) 4 (30) 2 (28) 4 DL 2 (29) 2 (27) 2 (29) 3 (30) 3 (30) 3 (20) 1 E Longitudinal vessels fray toward the base of the animal, making languets around the esophageal opening. Parastigmatic vessels are present and the number of stigmata range from five to six per mesh. Endocarps line the descending limb of the intestine; attached partially to the body wall and partially to the intestine. The endocarps are not fleshy, instead, they resemble parallel extensions of the intestine. They are not present in any other region of the body wall, neither on the gonadal lobes. The alimentary canal occupies the entire left side of the animal (Fig. 11D). The digestive gland is large, occupying a majority of the ascending limb of the intestine. The isodiametric intestine primary loop is close to the prepharyngeal groove. The anus is lobed and lies at the base atrial siphon (Fig. 11F). There is a thick membrane around the atrial siphon that always form four long projections, two of them anterior and two posterior. This membrane appears to have two different layers: an iridescent tissue that lies on a thicker tissue that makes up most of the membrane. The iridescent tissue does not have spinules and it is not present in some samples, likely due to the long length of fixation. In one sample, the flap also contained numerous calcareous spicules in the upper layer. Calcareous spicules in the shape of antlers were also seen on the wall of blood vessels and intestine of some specimens (Fig 11E). Gonad lobes are large and spherical; decreasing in size posteriorly. The number of lobes ranges from 12 to 22 on the left side. The right side of the animal is almost completely occupied by the large right gonad with 12 to 20 lobes (Fig. 11d). Gonoducts are long and open at the same level of the anus (Fig. 11F). Remarks. In the field, Pyura lopezlegentilae can be confused with P. longispina due to the same size, round shape and red coloration of the siphons. However, no other Pyura species is known to have the conspicuous yellow flap that is visible through the atrial siphon of P. lopezlegentilae, and the internal view of the atrial velum show that its margin is indeed large and form long projections. Further, living P. longispina usually have a wider oral siphon than P. lopezlegentilae. Internally, the structure of the gonads is very different as well as the size and shape of spinules. Pyura lopezlegentilae has also the gut shape, gonad shape and presence of calcareous spicules in common with P. munita but P. munita is usually smaller (max diameter 3 cm), covered by sand, has fewer longitudinal vessels (216���265) and does not have endocarps (Monniot 1972, 1983). Monniot (1972) mentioned a divided atrial vellum but did not comment anything special about it and the atrial vellum of P. lopezlegentilae is a very regular and noticeable structure. We studied two individuals collected in Belize and identified by I. Goodbody as P. munita (USNM 1092832 and USNM 17600). They were smaller animals and the vellum covering the siphons were iridescent but when observed under the compound microscope no spinules were found, but instead, we observed a layer of regular structures like small tiles (Fig. 12). Thus we believe that P. lopezlegentilae and P. munita are two different species., Published as part of Rocha, Rosana M. & Counts, Bailey Keegan, 2019, Pyura (Tunicata: Ascidiacea: Pyuridae) on the coasts of Panama, pp. 491-513 in Zootaxa 4564 (2) on pages 502-505, DOI: 10.11646/zootaxa.4564.2.9, http://zenodo.org/record/2589400, {"references":["Monniot, C. (1972) Ascidies Stolidobranches des Bermudes. Bulletin du Museum National d'Histoire Naturelle, 3 e ser, 43 (57), 617 - 643.","Monniot, C. (1983) Ascidies littorales de Guadeloupe. VI. Pyuridae et Molgulidae. Bulletin du Museum National d'Histoire Naturelle, 4 e ser, A, 5 (4), 1021 - 1044."]}

Recent efforts have been taken to survey and describe the ascidian fauna of the Pacific and Atlantic coasts of Panama; however, the genus Pyura still remains poorly known. Sampling events have been occurring since 2003. In this research, we describe two new species from the Atlantic coast of Panama: P. longispina sp. nov., P. lopezlegentilae sp. nov., and two new species from the Pacific Coast of Panama: P. carmanae sp. nov. and P. imesa sp. nov. We also supply a tabular key for all the Pyura species found in Panama.

Pyura carmanae sp. nov. (Figures 1, 2) urn:lsid:zoobank.org:act: E0CB2AD6-478D-418C-A8A0-F05383594564 Pyura sp. aff. vittata: Tokioka, 1972: 399. Materials examined: Holotype: MZUSP553 one individual, Isla Canales de Tierra, Shark Point, 7��44'18���N 81��34'46.8���W, leg. R. M. Rocha, 10.01.2009. Paratype: DZUP PYU-127 seven individuals, Isla Canales, Shark Point, 7��44'18���N 81��34'46.8���W, leg. R. M. Rocha, 10.01.2009. Etymology. The name of the species is a homage to Mary Carman from Woods Hole Oceanographic Institution who coordinated the expedition that found the species and for her important work concerning the study and management of invasive ascidians. Description. Living specimens are yellow and wrinkled (Fig. 1A, D); often found under rocks attached by the posterior region of the left side. The animals are usually 3���4 cm long but can reach 5.5 cm by 2 cm and are very flat (the holotype 3.5 cm long and 2.5 cm in diameter). The siphons are bumpy, apical and can be close together with little space separating the two or a little separated with the atrial siphon more lateral. The oral siphon is typically longer than the atrial siphon, but length varies among individuals (Fig. 1D), and none of the siphons have spinules on the border or on their internal lining. After fixation, animals still retain the yellow coloration, but the tunic is white inside and presents many bumps and horizontal wrinkles; notably in the anterior half of the animal. The rough tunic is relatively thick (1���3 mm), and can show a tessellate pattern in the posterior half (Fig. 1E). The tunic is usually clean of encrustations, but some bryozoans and entoprocts sparsely cover the surface. The body wall coloration varies. In fresh specimens, red coloration can be seen on the siphons. After fixation, it is often white or a faint yellow. The musculature of the siphons is strong. Circular muscles are heavily dense around the siphons, making them contracted. Longitudinal fibers placed tightly together radiate from the siphons down the body resembling a continuous sheet of muscles, however, the U-shaped right gonad is often seen through the body wall (Fig. 1B, C). There are 22 laterally flattened oral tentacles in the holotype on a ring of strong circular muscles embedded in the body wall, but the number ranges from 20 to 30 among samples (Fig. 2C). Tentacles are in one or two size orders but some specimens the tentacles mainly show one size, with a few smaller in between. Tentacles are thin, have a larger base that tapers off towards the end, and mostly have second order ramifications only; however, third order ramifications were viewed in some samples. The prepharyngeal groove is made up of two equal size lamellae, very close to the line of tentacles, forming a shallow V around the dorsal tubercle, which can be completely hidden under the tentacles. The aperture of the dorsal tubercle is U-shaped. The dorsal lamina does not begin immediately after the dorsal tubercle; instead, a small distance separates the two. The dorsal lamina is composed of long languets; 80 in the holotype. The pharynx is attached to the body wall by slender vessels. The pharynx is uncolored with six folds per side (Fig. 2A). In some cases, the right side folds are higher than the left side, and the ventral folds are reduced. Although high, the folds are separated from each other and do not overlap. The holotype has 231 longitudinal vessels and the formula is (from right to left side): E 3 (8) 2 (13) 2 (16) 3 (19) 2 (20) 4 (21) 4 DL 1 (24) 3 (18) 0 (20) 3 (16) 3 (10) 8 (7) 6 E While another smaller (2.5 cm) exemplar had the following formula (177 vessels in total): E 3 (6) 4 (9) 4 (13) 3 (12) 3 (11) 3 (19) 5 DL 1 (16) 2 (14) 3 (15) 3 (14) 3 (10) 2 (6) 3 E Parastigmatic vessels are present in many regions of the pharynx. There are four to six stigmata per mesh in between folds, and four or five on folds (Fig. 2F). Dense, irregular shaped endocarps are present on both sides of the animal. Those on the right are attached to the body wall dorsal and anterior to the right gonad, but absent between the right gonad and endostyle. Those on the left are attached to the body wall dorsal and anterior to the gut loop and there are also a few endocarps inside the primary intestinal loop (Fig. 2B, E). Endocarps usually not present on the gut although in some specimens one or two small endocarps are on the descending intestinal wall. Endocarps are also present on the most anterior gonadal lobes. On several specimens, a few endocarps anteriorly placed looked to be storing an unknown substance. The primary intestinal loop is large, with the ascending intestine running along the endostyle, but does not extending up to the prepharyngeal groove, although it surpass the level of the anus; the descending intestine is short and forms a shallow secondary loop with the rectum extending all the way inside the atrial siphon in specimens with siphons closer to each other (Fig. 2B). In specimens with siphons a little bit more spaced, the primary loop is more narrow and the descending intestine longer, forming a more posterior secondary loop (Fig. 2E). The intestine is isodiametric, transparent, and there can be a constriction before the anus, which has a smooth rim, sometimes enrolled outwards (Fig. 2G). The digestive gland lies along the esophagus and stomach, with many small portions followed by a large and elongated mass of tubular projections, often yellow or green, with one connection with the stomach wall (Fig. 2D). The left gonad is spread inside the primary intestinal loop, the lobes have tubular connections with the main duct and are separated from each other (Fig. 2B). The left gonad has 18���35 lobes. The lobes vary in size, are irregularly shaped, although tend to be oval. The right gonad is ventral and forms a deep U in the posterior half of the animal, with 28���35 lobes (Fig. 2B). Oviduct and sperm duct are slightly lobed and equally long, opening right at the base of the atrial siphon (Fig. 2G). Remarks. Tokioka (1972) described 12 individuals of this species from Playas del Coco, Costa Rica as Pyura aff. vittata and he argued that character variation in P. vittata was not enough known at that time for the separation of that population as a new species. Indeed, the right gonad of P. carmanae has the same shape as in P. vittata, but the dilated rectum, presence of endocarps on the intestine and gonads, larger number of longitudinal vessels and presence of spinules in the siphons in P. vittata distinguishes this species from P. carmanae. Further, in Central America, P. vittata is only found in the Atlantic coast both on mangrove prop roots, coral reefs and artificial substrates (Rocha et al. 2005; Carman et al. 2011), while P. carmanae is only found under rocks in the Pacific coast. Thus, the known geographical distribution of this species extends north at least until Costa Rica. Pyura discrepans (Sluiter, 1898) known from Colombia and Martinique is similar to P. carmanae. Main differences are the brownish-red tunic, irregular stigmata in the pharynx, presence of abundant endocarps on the descending intestine in the holotype but not in the specimen from Martinique and gonadal lobes not well attached to the body wall in P. discrepans (see Sluiter 1898, Monniot 1983, Monniot 2018). Pyura ocellata Monniot, 2016 recently described from French Guiana is also similar to P. carmanae. Main differences are the smaller size, short siphons, smaller number of stigmata per mesh, larger digestive track, larger number of gonadal lobes in P. ocellata (see Monniot, 2016). Among the samples in the Smithsonian Museum collection, USMN 0 14621 and USMN 0 14666 collected from Venado Beach, Panama and identified as P. vittata, actually belong in this species., Published as part of Rocha, Rosana M. & Counts, Bailey Keegan, 2019, Pyura (Tunicata: Ascidiacea: Pyuridae) on the coasts of Panama, pp. 491-513 in Zootaxa 4564 (2) on pages 492-494, DOI: 10.11646/zootaxa.4564.2.9, http://zenodo.org/record/2589400, {"references":["Tokioka, T. (1972) On a small collection of ascidians from the pacific coast of Costa Rica. Publications of the Seto Marine Biological Laboratory, 19 (6), 383 - 408. https: // doi. org / 10.5134 / 175738","Rocha, R. M., Moreno, T. R. & Faria, S. B. (2005) Ascidians from Bocas del Toro, Panama. I. Biodiversity. Caribbean Journal of Science, 41 (3), 600 - 612.","Carman, M. R., Bullard, S. G., Rocha, R. M., Lambert, G., Dijkstra, J. A., Roper, J. J., Goodwin, A., Carman, M. M. & Vail, E. M. (2011) Ascidians at the Pacific and Atlantic entrances to the Panama Canal. Aquatic Invasions, 6 (4), 371 - 380. https: // doi. org / 10.3391 / ai. 2011.6.4.02","Sluiter, C. P. (1898) Tuniciers recueillis en 1896 par La Chazalie dans la Mers des Antilles. Memoires de la Societe Zoologique de France, 11, 5 - 34.","Monniot, C. (1983) Ascidies littorales de Guadeloupe. VI. Pyuridae et Molgulidae. Bulletin du Museum National d'Histoire Naturelle, 4 e ser, A, 5 (4), 1021 - 1044.","Monniot, F. (2018) Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae. Zootaxa, 4459 (3), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4459.3.1","Monniot, F. (2016) Ascidians (Tunicata) of the French Guiana Expedition. Zootaxa, 4114 (3), 201 - 245. https: // doi. org / 10.11646 / zootaxa. 4114.3.1"]}

Pyura lignosa Michaelsen, 1908 (Figures 5, 6) Pyura (Halocynthia) lignosa Michaelsen, 1908: 256, pl.1, fig. 9; pl. 2, figs 21, 22 Pyura lignosa: Monniot, 1994: 44, fig. 1; Van Name, 1945: 336 (part) Material Examined: DZUP PYU-144, Isla Canales de Tierra, 7��44'39.7���N 81��34'45.2���W, leg. R. M. Rocha, 0 8.01.2009. Description. This Pacific species is common in the region in shallow waters 2���5 m deep (low tide). It was found on rocky substrates in mainland, Isla Canales de Tierra and Isla Canales de Afuera, but only one sample was collected due to the difficulty of detaching the animal from the substrate. It is extremely camouflaged by encrustations on the dark tunic, which is thick and hard. The siphons are red with four small lobes, but they are situated in depressions in the tunic (Figs 5A, B), and when closed, it is impossible to spot the animal on the substrate. The size of our specimen with tunic was 7.5 x 6.5 x 7 cm, but larger and smaller animals were seen in the field. The body wall is thick and opaque because the musculature forms a dense net of fibers in all directions (Figs 5C, D). Longitudinal muscles run from the siphons until the ventral margin. The atrial siphon is at half distance from the posterior region. The internal velum of the oral siphon has undulations covering the whole siphon, and there is a layer of tunic between the velum and the siphon musculature. The anterior third of the siphon lining is covered by spinules 50 ��m long (Figs 6C, G). There are 16 oral tentacles, flat and triangular. The first order ramifications appear along the posterior margin of the tentacle and are longer, while the second order ramifications are short and third order are minute (Fig. 6F). The dorsal tubercle is rounded, not protruding, with meandering aperture, while the peritubercle area forms a deep V (Fig. 6D). The dorsal lamina is divided in short triangular languets, 101 in total, many of which are not aligned (two or three were seen side by side). The languets are very delicate and break easily when touched. The pharynx has six folds in each side and they are high but almost do not overlap. The folds on the left side are more curved than the ones on the right side (Fig. 6A). A total of 445 longitudinal vessels are distributed according the following formula (right to left): E 4 (18) 11 (25) 12 (30) 15 (34) 8 (30) 10 DL 20 (27) 10 (33) 9 (35) 10 (32) 13 (28) 10 (16) 5 E There is a large amount of short vessels linking the pharynx with the body wall or with other organs, meaning that the atrial cavity is small. Also we confirm the thick tissue and projections described by Monniot (1994) on the atrial side of the pharynx, along the dorsal region (Fig. 6E). The alimentary canal forms a wide first loop occupying the whole left side, and a short and close secondary loop (Fig. 6B). There are a few large endocarps on the intestinal wall and also on the gonads. The green digestive gland forms one large portion. The anus contains a typhlosole, but the margin is smooth. The gonads are large and occupy most of the space of the atrial cavity in each side. They do not form well individualized lobes. Remarks. Except by small differences in the number of tentacles and longitudinal vessels, this specimen agrees well with the description of P. lignosa by Monniot (1994). The individuals from Gulf of California and Nicaragua studied by Van Name (1945) and reported under the name P. lignosa do not seem to belong to this species and should be reviewed to have their identity correctly determined., Published as part of Rocha, Rosana M. & Counts, Bailey Keegan, 2019, Pyura (Tunicata: Ascidiacea: Pyuridae) on the coasts of Panama, pp. 491-513 in Zootaxa 4564 (2) on pages 497-498, DOI: 10.11646/zootaxa.4564.2.9, http://zenodo.org/record/2589400, {"references":["Michaelsen, W. (1908) Die Pyuriden [Halocynthiiden] des NaturhistorischenMuseums zu Hamburg. Jahrbuch der Hamburgischen Wissenschaftlichen Anstalten, 25, suppl. 2, 227 - 287.","Monniot, C. (1994) Pyura lignosa (s. s.), a Pacific ascidian from Central American, with descriptions of species confused under this name. Zoological Journal of the Linnean Society, 110, 41 - 51. https: // doi. org / 10.1111 / j. 1096 - 3642.1994. tb 01470. x","Van Name, W. G. (1945) The North and South American ascidians. Bulletin of the American Museum of Natural History, 84, 1 - 476."]}

Pyura vannamei Monniot C., 1994 (Figures 13, 14) Pyura vananmei Monniot C., 1994: 47, fig.2; Monniot C., 1983: 1032, fig. 4; Monniot F., 2018: 419, figs 19, 20 not Pyura lignosa: Tokioka, 1972: 403, fig. 10, 65���70 (= P. imesa) Materials Examined: DZUP PYU-84, Isla Pastores, Bocas del Toro, 9��14'N, 82��20'W, leg. R. M. Rocha, 10.08.2003; DZUP PYU-85, Punta Vieja, Bastimentos, Bocas del Toro, 9��17.45'N, 82��05.38'W, leg. R. M. Rocha, 12.08.2003; DZUP PYU-86, Isla Cristobal, Bocas del Toro, 9��17���19.7���N 82��15���14.9���W, leg. G. Jerome, 12.08.2003; DZUP PYU-108, Isla Pastores, Bocas del Toro, 9��14'19.9���N 82��19'58.1���W, leg. R. M. Rocha, 17.08.2006; DZUP PYU-131, Isla Pastores, Bocas del Toro, 9��14'N 82��20'W, leg. R. M. Rocha, 17.08.2006; DZUP PYU-132, Isla Pastores, Bocas del Toro, 9��14'N, 82��20'W, leg. R. M. Rocha, 17.08.2006; DZUP PYU-150 Crawl Key, Bocas del Toro leg. R. M. Rocha, 25.08.2006; DZUP PYU-151 Crawl Key, Bocas del Toro leg. R. M. Rocha, 25.08.2006; DZUP PYU-105, Solarte, Bocas del Toro, 9��16'38.9���N 82��12'24.1���W, leg. R. M. Rocha, 19.06.2014; DZUP PYU-107, Hospital Point, Solarte, Bocas del Toro, 9��20'07���N 82��13'6.8���W, leg. R. M. Rocha, 16.06.2011. Description. Living specimens are purple colored with epibionts sparsely covering the tunic but after preservation, the tunic turns red (Fig. 13). The tunic is wrinkled. The animals attach on corals by the ventral margin and live in a vertical position with both siphons facing up, 1���3 m deep. The siphons are distant from each other with the oral siphon being slightly larger than the atrial, both lined with tubercles. Animals are commonly 2���3 cm in diameter and can reach up to 11.5 cm at maximum length including the tunic, but most specimens are 6���8 cm long. The thickness of the tunic is 1���3 mm. It has a white, reddish or purple interior. The body wall is uncolored and transparent around the gonadal and intestinal region, but when the material is freshly preserved, a red layer of tunic can be difficult to detach of the body wall. The siphons are red and densely surrounded by circular muscles. Longitudinal muscles organized into broad bands and radiate from the siphons down to the beginning of the gut on the left side and the gonad, on the right side, thus the enlarged intestinal pouch and long gonads are visible through the body wall (Fig. 13B, C). The lining of the siphons is red, without spinules, but with round white iridescent structures. The number of oral tentacles ranges from 18 to 33 (without counting very small ones), of four sizes. One large (11 cm long) individual had two very long ventral tentacles (1 cm), ~30 large and medium sizes and ~10 very thin and small tentacles. They are laterally flat, with a very large base. First order branches are long and placed along the posterior margin, with small second order ramifications, and occasionally minute third order branches (Fig. 14A). The peritubercle region is a deep V with a long dorsal tubercle with narrow U-shaped aperture (Fig. 14B). The first dorsal folds in each side begin posterior to the peritubercle region and the languets of the dorsal lamina appear posterior to those folds. The languets are thin and long, 55���98. The length of the languets increases posteriorly and each languet lines up with the transverse vessels of the pharynx. The pharynx is white and presents six high folds per side with no fold overlap, the dorsal ones not so high as the others (Fig. 13D). The vessel formula of a 4 cm long individual was (from right to left side���352 total): E 6 (24) 4 (25) 5 (25) 4 (28) 4 (25) 4 (20) 3 DL 4 (22) 7 (24) 4 (29) 4 (28) 6 (22) 6 (17) 2 E. and in an 11 cm long individual was (449 total): E 9 (25) 9 (29) 8 (29) 7 (35) 11 (25) 12 (25) 6 DL 5 (26) 10 (34) 7 (30) 8 (30) 10 (26) 7 (24) 2 E. Longitudinal vessels fray toward the base of the animal, making languets around the esophageal opening. Parastigmatic vessels are present and there are 4���7 stigmata per mesh (Fig. 14F). Fleshy large endocarps line both ascending and descending intestine, attached both to the body wall and intestine wall, but inside the secondary loop they are attached to the body wall only. The endocarps lining the ascending intestine are smaller and flatter. Very long laminar and irregular endocarps are observed on the top of each lobe on the left gonad but much smaller endocarps are observed on the right gonad. Four or five large fleshy endocarps, orange in recently preserved samples, are on the body wall, closely placed dorsally to the right gonad or much more centered along the middle longitudinal line (Fig. 13E, 14C). The gut loop occupies the 2/3 of the left side of the body and is entirely attached to the body wall (Fig. 13E). The intestine forms a closed primary loop, followed by an open secondary loop. The intestine is not isodiametric; a large pouch occupies the descending intestine and rectum. The anus is lobed (Fig. 14D). The digestive gland is green or brown and form a main portion with two connections to the stomach and small extensions connect to the long esophagus (Fig 14E). Both gonads are elongated and formed by a sequence of lined lobes which are not well defined in some sections. Testis follicles are finger-like and ramified, laying on the atrial side of the lobes. The left gonad is sometimes hidden by the large hind intestine and have around 30 lobes. The right gonad is ventral and lies extremely close to the endostyle, but forms a closed curve in the posterior end towards the atrial siphon. There are also around 30 lobes (Fig. 14C). Larger specimens do not have more gonadal lobes than smaller ones. The sperm duct is slightly shorter than the oviduct and open in the base of the atrial siphon (Fig. 14E). Remarks. Externally, this species resembles Pyura beta in the field due to coloration and distant siphons. Internally, the most significant difference between P. beta and P. vannamei is the enlarged intestine present only in P. vannamei, but the lobed anus, endocarps attached to the intestine wall and the large fleshy endocarps that lie dorsally next to the right gonad are also indicative of P. vannamei. Our specimens agree well with the description by Monniot (1994), but his Fig. 2A shows a very shallow peritubercle region which is usually very deep and narrow in Panamanian specimens., Published as part of Rocha, Rosana M. & Counts, Bailey Keegan, 2019, Pyura (Tunicata: Ascidiacea: Pyuridae) on the coasts of Panama, pp. 491-513 in Zootaxa 4564 (2) on pages 506-508, DOI: 10.11646/zootaxa.4564.2.9, http://zenodo.org/record/2589400, {"references":["Monniot, C. (1994) Pyura lignosa (s. s.), a Pacific ascidian from Central American, with descriptions of species confused under this name. Zoological Journal of the Linnean Society, 110, 41 - 51. https: // doi. org / 10.1111 / j. 1096 - 3642.1994. tb 01470. x","Monniot, C. (1983) Ascidies littorales de Guadeloupe. VI. Pyuridae et Molgulidae. Bulletin du Museum National d'Histoire Naturelle, 4 e ser, A, 5 (4), 1021 - 1044.","Monniot, F. (2018) Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae. Zootaxa, 4459 (3), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4459.3.1","Tokioka, T. (1972) On a small collection of ascidians from the pacific coast of Costa Rica. Publications of the Seto Marine Biological Laboratory, 19 (6), 383 - 408. https: // doi. org / 10.5134 / 175738"]}

Pyura beta sp. nov. (Figs. 1–4) Material examined: Holotype: MZUSP552 Isla Solarte, mangrove roots, R. M. Rocha, 7/VI/2009 Paratypes: MZUSP 0 0 0 41, Baleeiro south point, São Sebastião, SP, 23/V/1961, Calypso Expedition; DZUP—PYU-022 Cabras Island, São Sebastião, SP, 16/II/1997, 1 ind., R.M. Rocha; DZUP PYU-53, Oratório Bay, Alcatrazes Island, SP, 2/V/2002, 1 ind., R.M. Rocha; DZUP PYU-100, Crawl Key, Bocas del Toro, R. M. Rocha, 25/VIII/2006; DZUP PYU-99, Bastimentos, Bocas del Toro, R. M. Rocha, 4/VIII/2008; DZUP PYU-102 Isla Solarte, Bocas del Toro, R. M. Rocha, 7/ VI /2009; DZUP PYU-101, Isla Solarte, Bocas del Toro, R. M. Rocha, 11/ VI /2009; DZUP PYU-104, Solarte, Bocas del Toro, R. M. Rocha, 10/ VI /2011; DZUP PYU-75, Escalvada Island, Guarapari, ES, 27/I/2012, 1 ind., G.A. Gamba; MZUSP557, Amarração Island, Angra dos Reis, 13/III/2014, 1 ind., L.F.Skinner; CZFFP-ASC38 Sardinhas Bay, Angra dos Reis, 13/III/2014, 1 ind., L.F. Skinner; CZFFP-ASC39 Comprida Island, Cabo Frio, RJ, 6/V/2014, 1 ind., L.F. Skinner; DZUP PYU-103, Solarte, Bocas del Toro, R. M. Rocha, 19/ VI /2014. Additional material: DZUP PYU-95 Vitória Island, São Sebastião, SP, 8/IX/1998, 1 ind., R.M. Rocha; DZUP PYU-57, Montão de Trigo Island, São Sebastião, SP, 1/V/2002, 1 ind., 10-12m, R.M. Rocha; DZUP PYU-138, Bastimentos, Bocas del Toro, R. M. Rocha, 4/VIII/2008; DZUP PYU-137, STRI Bay, Bocas del Toro, R. M. Rocha, 5/IX/2008; DZUP PYU-66 and Pyu-64, Sumítica Island, São Sebastião, SP, 2/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-63, Ponta Grossa bay, Ilha Bela, SP, 03/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-65, Serraria Island, São Sebastião, SP; 4/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-130, Bastimentos, Bocas del Toro, R. M. Rocha, 27/I/2009; DZUP PYU-96, Escalvada Island, Guarapari, ES, 27/I/2012, 1 ind., R.M. Rocha; CZFFP- ASC42 Parnaioca bay, Grande Island, Angra do Reis, RJ, 4/ VI /2013, 1 ind., L.F. Skinner; CZFFP-ASC40 Lopes Mendes beach, Grande Island, Angra dos Reis, RJ, 5/ VI /2013, 5 ind., L.F. Skinner; CZFFP-ASC41 Jorge Grego Island, Angra dos Reis, RJ, 6/ VI /2013, 1ind., L.F. Skinner; DZUP PYU-98, Palmeiras Point, Grande Island, RJ, 10/ IX/2013, 1 ind, L.F. Skinner; DZUP PYU-97, Jorge Grego Island, Angra dos Reis, RJ, 11/IX/2013, 2 ind., L.F. Skinner; CZFFP-ASC43 Dois Rios bay, Grande Island, Angra dos Reis, RJ, 12/IX/2013, 2 ind., L.F. Skinner; DZUP PYU-94 Papagaios Island, Cabo Frio, RJ, 09/V/2014, 2 ind., L.F. Skinner. Etymology. The species name is derived from the coloration of the tunic in resemblance to that of the common beet, Beta vulgaris. Description. Living specimens present dark red or wine coloration often resembling the coloration of a beet (Fig. 1A, B, C), sometimes with a tinge of yellow towards the base of the animal. It loses some coloration after a long fixation. The tunic is hard, 2–3 mm thick, with divisions forming small patches on the surface (Fig. 1D), and frequently, but not always, masked by epibionts and debris. The animal is elongated and attaches along the ventral margin to mangrove prop roots, to exposed coral skeleton or rocky walls in shallow waters (less than 5 m in Panama but to 15 m in Brazil), in a vertical position, with the oral siphon apical and the atrial siphon short and posterior. The siphons are surrounded by tubercles (Fig. 1C). The holotype is 11 cm in total length, but individuals from 7 to 8 cm long are more common and this was the maximum size found in Brazil. The color of the inner tunic lining depends on the duration of fixation. Freshly fixed specimens present red or wine coloration; however, over the course of time, the tunic shows a gradient from red to white. With the tunic removed, the holotype is 8.5 cm at the longest length; the oral siphon is 2 cm long and the atrial siphon is 1.5 cm long. Body wall musculature is robust. Thick longitudinal bands composed of many muscle fibers radiate from the siphons and terminate at the level of the gonadal and intestinal region, where those bands divide into numerous thinner fibers leaving this area more transparent (Fig. 2A, B, D). The number of muscle bands varies; the right side of the body often has 21–24 bands, and the left side 23–25. Circular musculature around the siphons is also very strong and forms wide bands at the base of both siphons covering the longitudinal bands. The siphons present a variation of red and yellow in recently preserved animals. Internally, the siphons have a velum, but spinules are absent. Oral tentacles are uncolored, laterally flattened, and triangular with a very wide base. First order ramifications are arranged in a line along the posterior margin, and second order ramifications are minute (Fig. 3A). Tentacles are in three different sizes, the largest circa 7 mm long, and the smallest usually attached along a line at a more posterior level. The number of tentacles ranges from 26 to 50 in the species; 18 large and medium tentacles and 30 smaller and displaced posteriorly in the holotype. A small distance separates the tentacles and the prepharyngeal groove, and this narrow region is smooth. The prepharyngeal groove is formed by two equal size lamellae that establish a very deep V where the dorsal tubercle is situated. The dorsal tubercle aperture is U or V-shaped, very narrow, lying deep in the V (Fig. 3B). The dorsal lamina starts after the insertion of the first right dorsal branchial fold and extends to the esophageal opening with 60–125 long languets, ~ 125 in the holotype. The length of the languets increases posteriorly (Fig. 3F). The pharynx is uncolored and transparent with six high folds per side (Figs. 2C, 3D). Fold overlap occurs on both sides, however, the folds on the right side of the holotype show more overlap than the left side. The holotype (11 cm) has 440 total longitudinal vessels and the longitudinal vessel formula is (from right to left): E 10 (17) 11 (30) 4 (32) 4 (36) 6 (33) 5 (25) 4 DL 3 (35) 10 (30) 7 (33) 8 (32) 9 (35) 10 (16) 5 E Other samples: Panama: E 5 (19) 4 (24) 7 (26) 5 (27) 4 (24) 5 (24) 4 DL 2 (21) 4 (22) 7 (26) 6 (24) 6 (23) 6 (24) 5 E MZUSP 557 (4 cm): E 6 (12) 2 (15) 4 (15) 4 (15) 4 (14) 2 (12) 2 DL 2 (12) 2 (16) 2 (16) 5 (14) 4 (12) 3 (11) 3 E DZUP PYU54 (4.5 cm): E 7 (17) 3 (22) 2 (21) 2 (22) 6 (14) 5 (14) 3 DL 2 (22) 3 (19) 2 (25) 1 (24) 2 (19) 1 (17) 8 E DZUP PYU75 (3.48 cm): E 6 (15) 3(17) 3 (20) 3 (19) 3 (13) 3 (17) 2 DL 2 (16) 1 (15) 2 (19) 2 (18) 3 (17) 2 (12) 4 E MZUSP 0 0 0 41 (3.5 cm): E 8 (10) 4 (16) 4 (16) 3 (16) 3 (16) 3 (15) DL 2 (17) 3 (12) 4 (16) 4 (19) 4 (13) 3 (10) E There are frequently five or six stigmata per mesh, both between and on folds, but some samples from Brazil had four. Parastigmatic vessels are present; however, not in every mesh and can be incomplete (Fig. 3E). Posteriorly languets extend around the right side of the esophageal opening; there are 45 of those languets in the holotype. The pharynx is attached to the body wall by numerous thick vessels. Significantly smaller ones attach the pharynx to the gonadal and intestinal regions. The intestine is isodiametric, and the primary intestinal loop extends anteriorly, sometimes two thirds to half of the distance to the peripharyngeal groove. The loop is narrow with parallel ascending and descending portions along the ventral margin (Fig. 2D). The secondary loop is very small and ends in a smooth anus (Fig. 3G). Sometimes, a slight constriction at the pre-anal region could be noted. Endocarps line the ascending and descending intestine, both inside and outside the loop. The ones ventral to the ascending intestine are laminar, very thin and circular, while those lining the descending intestine are fleshy, irregular and more numerous (Fig. 2D). Endocarps are also present attached to the body wall. A large digestive gland, 2 cm long in the holotype, shows two connections with the stomach; there are additional small portions on the esophagus (Fig. 3H). The atrial velum is red in freshly preserved animals, wide and waving, and without thread-like projections (Fig. 2D). The left gonad occupies the entire space of the first gut loop and contains 34 irregularly shaped lobes in the holotype, but the number of gonad lobes ranges from 34 to 62. They intermittently present fleshy endocarps on the top of the lobes. The right gonad is ventral and takes the form of a backward J. The right gonad extends up to the same position that the intestinal loop does on the left side (Fig. 2D), with 62 irregular shaped gonad lobes placed tightly together in the holotype, ranging from 38 to 82 lobes in other samples. The right gonad also has small endocarps on the tops of some lobes. Large and complex fleshy endocarps attached to the body wall line the anterior and dorsal sides of the right gonad. Gonoducts are short on both sides and the oviduct is lobed (Fig. 3G). Remarks. This species can be confused with Pyura vannamei because of the similar color of living animals and the elongated body with a posterior atrial siphon. The distribution of P. vannamei is restricted to the Caribbean region and in the field, it has never been found on mangrove roots. It generally lies horizontally on the ventral side with both siphons up while P. beta generally lies vertically on coral heads or mangrove roots, with the oral siphon up and the atrial siphon posterior and lateral. Pyura beta living color is usually redder and P. vannamei is usually more purple, but both tend to red after preservation in formalin. The two species also differ in that P. beta has colored muscles when fresh and an isodiametric intestine with small secondary loop and smooth anus, whereas P. vannamei has white muscles in fresh samples and an enlarged hind pouch in the second loop, and lobed anus (Monniot 1994). Pyura beta was first collected from the Brazilian coast in 1961 during an R.V. Calypso expedition and deposited on MZUSP as P. vittata by Sérgio A. Rodrigues (Rodrigues 1966). In 1997 one of us (R.M. Rocha) collected two individuals at Cabras Island, São Sebastião, SP, but also identified them as P. vittata (DZUP PYU- 22). Since then, many other individuals from the southwestern Atlantic have been collected, mainly from some coastal islands. Brazilian specimens are light reddish to yellow, but all other features are similar with Caribbean ones (Fig. 4). They have been identified as P. vittata but both species are different in many aspects: P. vittata is more or less globular in shape, the tunic is thin and white internally, the siphons are closer when compared to P. beta with long (up to 0.32 mm) and iridescent s pinules noticeable even on the outside of the siphons (Monniot 2018), and the body musculature is less developed. Also, in P. vittata, the right gonad is in a more median portion of the body and it is more dorsally curved (Monniot 1983). In a short visit to the Smithsonian Collection in Washington, DC we had the opportunity to see some samples and it is possible that the specimens USNM 21805 and USNM 1090900 collected in Pelican Bay, Belize and identified by I. Goodbody as Pyura lignosa may be P. beta. External appearance looks exactly the same but there was not enough time for a complete dissection. Goodbody (2000) mentions animals exceeding 15 cm in length. If this identification is confirmed the geographical distribution of the species is enlarged. Monniot (2016) recently reported P. vittata from French Guiana but the description given resembles P. beta, except for the smaller size and color of preserved animals. The animals do not have the enlarged posterior intestinal region and the author does not mention the presence of siphonal spines, both characteristics typical of P. vittata (see Monniot 1983).

Pyura beta sp. nov. (Figs. 1���4) Material examined: Holotype: MZUSP552 Isla Solarte, mangrove roots, R. M. Rocha, 7/VI/2009 Paratypes: MZUSP 0 0 0 41, Baleeiro south point, S��o Sebasti��o, SP, 23/V/1961, Calypso Expedition; DZUP���PYU-022 Cabras Island, S��o Sebasti��o, SP, 16/II/1997, 1 ind., R.M. Rocha; DZUP PYU-53, Orat��rio Bay, Alcatrazes Island, SP, 2/V/2002, 1 ind., R.M. Rocha; DZUP PYU-100, Crawl Key, Bocas del Toro, R. M. Rocha, 25/VIII/2006; DZUP PYU-99, Bastimentos, Bocas del Toro, R. M. Rocha, 4/VIII/2008; DZUP PYU-102 Isla Solarte, Bocas del Toro, R. M. Rocha, 7/ VI /2009; DZUP PYU-101, Isla Solarte, Bocas del Toro, R. M. Rocha, 11/ VI /2009; DZUP PYU-104, Solarte, Bocas del Toro, R. M. Rocha, 10/ VI /2011; DZUP PYU-75, Escalvada Island, Guarapari, ES, 27/I/2012, 1 ind., G.A. Gamba; MZUSP557, Amarra����o Island, Angra dos Reis, 13/III/2014, 1 ind., L.F.Skinner; CZFFP-ASC38 Sardinhas Bay, Angra dos Reis, 13/III/2014, 1 ind., L.F. Skinner; CZFFP-ASC39 Comprida Island, Cabo Frio, RJ, 6/V/2014, 1 ind., L.F. Skinner; DZUP PYU-103, Solarte, Bocas del Toro, R. M. Rocha, 19/ VI /2014. Additional material: DZUP PYU-95 Vit��ria Island, S��o Sebasti��o, SP, 8/IX/1998, 1 ind., R.M. Rocha; DZUP PYU-57, Mont��o de Trigo Island, S��o Sebasti��o, SP, 1/V/2002, 1 ind., 10-12m, R.M. Rocha; DZUP PYU-138, Bastimentos, Bocas del Toro, R. M. Rocha, 4/VIII/2008; DZUP PYU-137, STRI Bay, Bocas del Toro, R. M. Rocha, 5/IX/2008; DZUP PYU-66 and Pyu-64, Sum��tica Island, S��o Sebasti��o, SP, 2/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-63, Ponta Grossa bay, Ilha Bela, SP, 03/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-65, Serraria Island, S��o Sebasti��o, SP; 4/XII/2008, 1 ind., L.P. Kremer; DZUP PYU-130, Bastimentos, Bocas del Toro, R. M. Rocha, 27/I/2009; DZUP PYU-96, Escalvada Island, Guarapari, ES, 27/I/2012, 1 ind., R.M. Rocha; CZFFP- ASC42 Parnaioca bay, Grande Island, Angra do Reis, RJ, 4/ VI /2013, 1 ind., L.F. Skinner; CZFFP-ASC40 Lopes Mendes beach, Grande Island, Angra dos Reis, RJ, 5/ VI /2013, 5 ind., L.F. Skinner; CZFFP-ASC41 Jorge Grego Island, Angra dos Reis, RJ, 6/ VI /2013, 1ind., L.F. Skinner; DZUP PYU-98, Palmeiras Point, Grande Island, RJ, 10/ IX/2013, 1 ind, L.F. Skinner; DZUP PYU-97, Jorge Grego Island, Angra dos Reis, RJ, 11/IX/2013, 2 ind., L.F. Skinner; CZFFP-ASC43 Dois Rios bay, Grande Island, Angra dos Reis, RJ, 12/IX/2013, 2 ind., L.F. Skinner; DZUP PYU-94 Papagaios Island, Cabo Frio, RJ, 09/V/2014, 2 ind., L.F. Skinner. Etymology. The species name is derived from the coloration of the tunic in resemblance to that of the common beet, Beta vulgaris. Description. Living specimens present dark red or wine coloration often resembling the coloration of a beet (Fig. 1A, B, C), sometimes with a tinge of yellow towards the base of the animal. It loses some coloration after a long fixation. The tunic is hard, 2���3 mm thick, with divisions forming small patches on the surface (Fig. 1D), and frequently, but not always, masked by epibionts and debris. The animal is elongated and attaches along the ventral margin to mangrove prop roots, to exposed coral skeleton or rocky walls in shallow waters (less than 5 m in Panama but to 15 m in Brazil), in a vertical position, with the oral siphon apical and the atrial siphon short and posterior. The siphons are surrounded by tubercles (Fig. 1C). The holotype is 11 cm in total length, but individuals from 7 to 8 cm long are more common and this was the maximum size found in Brazil. The color of the inner tunic lining depends on the duration of fixation. Freshly fixed specimens present red or wine coloration; however, over the course of time, the tunic shows a gradient from red to white. With the tunic removed, the holotype is 8.5 cm at the longest length; the oral siphon is 2 cm long and the atrial siphon is 1.5 cm long. Body wall musculature is robust. Thick longitudinal bands composed of many muscle fibers radiate from the siphons and terminate at the level of the gonadal and intestinal region, where those bands divide into numerous thinner fibers leaving this area more transparent (Fig. 2A, B, D). The number of muscle bands varies; the right side of the body often has 21���24 bands, and the left side 23���25. Circular musculature around the siphons is also very strong and forms wide bands at the base of both siphons covering the longitudinal bands. The siphons present a variation of red and yellow in recently preserved animals. Internally, the siphons have a velum, but spinules are absent. Oral tentacles are uncolored, laterally flattened, and triangular with a very wide base. First order ramifications are arranged in a line along the posterior margin, and second order ramifications are minute (Fig. 3A). Tentacles are in three different sizes, the largest circa 7 mm long, and the smallest usually attached along a line at a more posterior level. The number of tentacles ranges from 26 to 50 in the species; 18 large and medium tentacles and 30 smaller and displaced posteriorly in the holotype. A small distance separates the tentacles and the prepharyngeal groove, and this narrow region is smooth. The prepharyngeal groove is formed by two equal size lamellae that establish a very deep V where the dorsal tubercle is situated. The dorsal tubercle aperture is U or V-shaped, very narrow, lying deep in the V (Fig. 3B). The dorsal lamina starts after the insertion of the first right dorsal branchial fold and extends to the esophageal opening with 60���125 long languets, ~ 125 in the holotype. The length of the languets increases posteriorly (Fig. 3F). The pharynx is uncolored and transparent with six high folds per side (Figs. 2C, 3D). Fold overlap occurs on both sides, however, the folds on the right side of the holotype show more overlap than the left side. The holotype (11 cm) has 440 total longitudinal vessels and the longitudinal vessel formula is (from right to left): E 10 (17) 11 (30) 4 (32) 4 (36) 6 (33) 5 (25) 4 DL 3 (35) 10 (30) 7 (33) 8 (32) 9 (35) 10 (16) 5 E Other samples: Panama: E 5 (19) 4 (24) 7 (26) 5 (27) 4 (24) 5 (24) 4 DL 2 (21) 4 (22) 7 (26) 6 (24) 6 (23) 6 (24) 5 E MZUSP 557 (4 cm): E 6 (12) 2 (15) 4 (15) 4 (15) 4 (14) 2 (12) 2 DL 2 (12) 2 (16) 2 (16) 5 (14) 4 (12) 3 (11) 3 E DZUP PYU54 (4.5 cm): E 7 (17) 3 (22) 2 (21) 2 (22) 6 (14) 5 (14) 3 DL 2 (22) 3 (19) 2 (25) 1 (24) 2 (19) 1 (17) 8 E DZUP PYU75 (3.48 cm): E 6 (15) 3(17) 3 (20) 3 (19) 3 (13) 3 (17) 2 DL 2 (16) 1 (15) 2 (19) 2 (18) 3 (17) 2 (12) 4 E MZUSP 0 0 0 41 (3.5 cm): E 8 (10) 4 (16) 4 (16) 3 (16) 3 (16) 3 (15) DL 2 (17) 3 (12) 4 (16) 4 (19) 4 (13) 3 (10) E There are frequently five or six stigmata per mesh, both between and on folds, but some samples from Brazil had four. Parastigmatic vessels are present; however, not in every mesh and can be incomplete (Fig. 3E). Posteriorly languets extend around the right side of the esophageal opening; there are 45 of those languets in the holotype. The pharynx is attached to the body wall by numerous thick vessels. Significantly smaller ones attach the pharynx to the gonadal and intestinal regions. The intestine is isodiametric, and the primary intestinal loop extends anteriorly, sometimes two thirds to half of the distance to the peripharyngeal groove. The loop is narrow with parallel ascending and descending portions along the ventral margin (Fig. 2D). The secondary loop is very small and ends in a smooth anus (Fig. 3G). Sometimes, a slight constriction at the pre-anal region could be noted. Endocarps line the ascending and descending intestine, both inside and outside the loop. The ones ventral to the ascending intestine are laminar, very thin and circular, while those lining the descending intestine are fleshy, irregular and more numerous (Fig. 2D). Endocarps are also present attached to the body wall. A large digestive gland, 2 cm long in the holotype, shows two connections with the stomach; there are additional small portions on the esophagus (Fig. 3H). The atrial velum is red in freshly preserved animals, wide and waving, and without thread-like projections (Fig. 2D). The left gonad occupies the entire space of the first gut loop and contains 34 irregularly shaped lobes in the holotype, but the number of gonad lobes ranges from 34 to 62. They intermittently present fleshy endocarps on the top of the lobes. The right gonad is ventral and takes the form of a backward J. The right gonad extends up to the same position that the intestinal loop does on the left side (Fig. 2D), with 62 irregular shaped gonad lobes placed tightly together in the holotype, ranging from 38 to 82 lobes in other samples. The right gonad also has small endocarps on the tops of some lobes. Large and complex fleshy endocarps attached to the body wall line the anterior and dorsal sides of the right gonad. Gonoducts are short on both sides and the oviduct is lobed (Fig. 3G). Remarks. This species can be confused with Pyura vannamei because of the similar color of living animals and the elongated body with a posterior atrial siphon. The distribution of P. vannamei is restricted to the Caribbean region and in the field, it has never been found on mangrove roots. It generally lies horizontally on the ventral side with both siphons up while P. beta generally lies vertically on coral heads or mangrove roots, with the oral siphon up and the atrial siphon posterior and lateral. Pyura beta living color is usually redder and P. vannamei is usually more purple, but both tend to red after preservation in formalin. The two species also differ in that P. beta has colored muscles when fresh and an isodiametric intestine with small secondary loop and smooth anus, whereas P. vannamei has white muscles in fresh samples and an enlarged hind pouch in the second loop, and lobed anus (Monniot 1994). Pyura beta was first collected from the Brazilian coast in 1961 during an R.V. Calypso expedition and deposited on MZUSP as P. vittata by S��rgio A. Rodrigues (Rodrigues 1966). In 1997 one of us (R.M. Rocha) collected two individuals at Cabras Island, S��o Sebasti��o, SP, but also identified them as P. vittata (DZUP PYU- 22). Since then, many other individuals from the southwestern Atlantic have been collected, mainly from some coastal islands. Brazilian specimens are light reddish to yellow, but all other features are similar with Caribbean ones (Fig. 4). They have been identified as P. vittata but both species are different in many aspects: P. vittata is more or less globular in shape, the tunic is thin and white internally, the siphons are closer when compared to P. beta with long (up to 0.32 mm) and iridescent s pinules noticeable even on the outside of the siphons (Monniot 2018), and the body musculature is less developed. Also, in P. vittata, the right gonad is in a more median portion of the body and it is more dorsally curved (Monniot 1983). In a short visit to the Smithsonian Collection in Washington, DC we had the opportunity to see some samples and it is possible that the specimens USNM 21805 and USNM 1090900 collected in Pelican Bay, Belize and identified by I. Goodbody as Pyura lignosa may be P. beta. External appearance looks exactly the same but there was not enough time for a complete dissection. Goodbody (2000) mentions animals exceeding 15 cm in length. If this identification is confirmed the geographical distribution of the species is enlarged. Monniot (2016) recently reported P. vittata from French Guiana but the description given resembles P. beta, except for the smaller size and color of preserved animals. The animals do not have the enlarged posterior intestinal region and the author does not mention the presence of siphonal spines, both characteristics typical of P. vittata (see Monniot 1983)., Published as part of Skinner, Lu��s Felipe, Rocha, Rosana M. & Counts, Bailey K., 2019, Pyura gangelion and Pyura beta sp. nov. (Ascidiacea: Pyuridae): an exotic and a new tunicate from the West Atlantic, pp. 264-276 in Zootaxa 4545 (2) on pages 265-271, DOI: 10.11646/zootaxa.4545.2.6, http://zenodo.org/record/2618831, {"references":["Monniot, C. (1994) Pyura lignosa (s. s.), a Pacific ascidian from Central American, with descriptions of species confused under this name. Zoological Journal of the Linnean Society, 110, 41 - 51. https: // doi. org / 10.1111 / j. 1096 - 3642.1994. tb 01470. x","Rodrigues, S. A. (1966) Notes on Brazilian ascidians. Papeis Avulsos do Departamento de Zoologia da Universidade de Sao Paulo, 19, 95 - 115.","Monniot, F. (2018) Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae. Zootaxa, 4459 (3), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4459.3.1","Monniot, C. (1983) Ascidies littorales de Guadeloupe. VI. Pyuridae et Molgulidae. Bulletin du Museum National D'Histoire Naturelle, 4 e Series, A, 5 (4), 1021 - 1044.","Goodbody, I. (2000) Diversity and distribution of ascidians (Tunicata) in the Pelican Cays, Belize. Atoll Research Bulletin, 480, 302 - 326. https: // doi. org / 10.5479 / si. 00775630.480.","Monniot, F (2016) Ascidians (Tunicata) of the French Guiana Expedition. Zootaxa, 4114 (3), 201 - 245. https: // doi. org / 10.11646 / zootaxa. 4114.3.1"]}

Pyura gangelion (Savigny, 1816) Figs. 5–6 Cynthia gangelion Savigny, 1816. Pyura gangelion: Monniot 2018: 13, Fig. 12–15 and other synonyms Material examined. DZUP PYU 74, Escalvada Island, Guarapari, ES, 26/I/2012, 1 ind., R.M. Rocha; DZUP PYU-160 Escalvada Island, Guarapari, ES, 27/I/2012, 2 ind. R.M. Rocha; DZUP PYU-153, PYU-154, PYU-155 Rasa de Terra Island, Guarapari, ES, 23/III/2017, 1 ind. each, R.M. Rocha. Description. Animals are rounded with very long siphons, 4 to 7 cm in total length including the tunic. They attach to the substrate by the posterior region of the tunic. Tunic is leathery, 2 mm thick around the body but up to 5 mm thick when contracted around the siphons, and covered by many fouling organisms like algae, sponges, hydroids, polychaetes, colonial ascidians and others. The animal is reddish to wine color, with some orange areas and the tunic matrix is wine or pale wine with a mucous yellow membrane in contact with the animal epidermis (Fig. 5A). The siphons are located anteriorly. The oral siphon is shorter (1–2 cm) than the atrial (1.5–3.5 cm). Both siphons have four lobes covered by a layer of dense spinules measuring up to 200 µm (Fig. 5B, C, 6I) that extend from inside the siphons. The body wall is almost opaque because of the well developed muscles forming thin bands underneath a mat of fibers crossing each other in different directions and extend to the endostyle (Fig. 5D, E, 6A, B). In freshly preserved animals the anterior region of the body, including the siphons, is orange. The oral tentacles are laminar and curved, with dense ramifications up to second order along the posterior margin (Fig. 6H); the number ranges from 18 to 23, in three different sizes. The largest measure 7 mm. The prepharyngeal region is very narrow and smooth, and the prepharyngeal groove margins do not have projections. The peritubercular region is a deep V with the dorsal tubercle aperture heart-shaped or as a Y (Fig. 5I). The dorsal lamina is divided into many filamentous languets (73–112) and extends to the esophagus. The ends of the longitudinal vessels project towards the esophagus at both sides of its aperture, forming long languets. There are six high pharyngeal folds that overlap a little at each side of the body (Figs 5G, 6G). The number of longitudinal vessels ranges from 177–209 on the right side and 172–216 on the left. Transverse vessels 70 (only counted in one individual). Parastigmatic vessels are present. The number of stigmata ranges from four to six per mesh (Fig. 5H). The longitudinal vessel formula, from the right to left side in two different animals is: E 11 (23) 7 (24) 7 (24) 7 (24) 8 (24) 7 (27) 4 DL 4 (27) 5 (27) 5 (30) 5 (26) 5 (23) 4 (26) 8 E E 4 (25) 4 (24) 5 (30) 6 (32) 4 (26) 5 (26) 6 DL 5 (26) 5 (33) 5 (32) 7 (31) 6 (28) 4 (26) 8 E The gut occupies about 2/3 of the left side of the body. The digestive gland is one large mass formed by many tubular projections, brownish to light/dark green (Figs. 5F, 6F). There are three connections between the digestive gland and the intestine and small groups of projections along the esophagus. The intestine is isodiametric, with a first loop that is long and wide containing the left gonad and a short second loop. Fleshy and irregular-shaped, very dense endocarps are present from the anterior region close to the digestive gland, following the outer intestinal curvature to the anus (Figs 5F, 6D, E). Sometimes a slight constriction of the pre-anal region could be observed. The anus is sometimes bilobed, with smooth margins and opening very close to the atrial siphon (Fig. 5J). The atrial siphon velum forms four lobes projecting internally. On the right side, the gonad is attached to the center of the body wall; it is curved and when fully developed it can occupy most of the space. It is formed by 24–33 spherical or elongated lobes disposed irregularly along the oviduct (Figs 5E, F, 6D, E). The left gonad has 22–30 lobes organized in pairs in the wide portion of the loop (Fig. 5D, F, 6D, F). The oviduct and sperm duct run together for a short distance and open close to the atrial siphon on both sides. Endocarps on the gonadal lobes are irregular and smaller than the ones on the intestine, but there is a group of elongated endocarps around the anterior end of the right gonad and a line of endocarps along the heart, between the right gonad and the endostyle, especially noticeable in Fig. 6D, E. Remarks: Pyura gangelion is known from the Red Sea (Monniot 1973), Tanzania, Mozambique, Madagascar, Maldivas and many countries in the Indo-Pacific (Monniot & Monniot 2001). Monniot (2018) re-examined Pyura torpida from Martinique which has been previously studied by C. Monniot (1983) and decided that the correct identification should be P. gangelion, showing that the species has been introduced in the Atlantic for at least 35 years. The strong armature of spinules in the siphons, four lobed atrial velum, lack of endocarps on the body wall and the line of endocarps present along the heart are diagnostic features of this species (compare our Fig. 6D, E with Monniot (2018) Figs. 13A and 14C). The spinules have a similar shape as in P. vittata but are more iridescent in the latter. It also differs from P. vittata mainly by the shape of the body (more round), stronger body wall musculature, rectum not dilated and the line of endocarps along the heart (Monniot 1983). The very long siphons of the specimens found in Brazil make it similar to Microcosmus exasperatus Heller, 1878 in the field., Published as part of Skinner, Luís Felipe, Rocha, Rosana M. & Counts, Bailey K., 2019, Pyura gangelion and Pyura beta sp. nov. (Ascidiacea: Pyuridae): an exotic and a new tunicate from the West Atlantic, pp. 264-276 in Zootaxa 4545 (2) on pages 271-273, DOI: 10.11646/zootaxa.4545.2.6, http://zenodo.org/record/2618831, {"references":["Monniot, F. (2018) Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae. Zootaxa, 4459 (3), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4459.3.1","Monniot, C. (1973) Redescription de six ascidies du Golf d'Elat recoltees par H. Schuhmacher. Israel Journal of Zoology, 22, 51 - 62.","Monniot, F. & Monniot, C. (2001) Ascidians from the tropical western Pacific. Zoosystema, 23, 201 - 383.","Monniot, C. (1983) Ascidies littorales de Guadeloupe. VI. Pyuridae et Molgulidae. Bulletin du Museum National D'Histoire Naturelle, 4 e Series, A, 5 (4), 1021 - 1044."]}

The genus Pyura is widely distributed with 99 valid species. Since 1961, Pyura vittata (Stimpson, 1852) has been reported to the Southwest Atlantic but new collections and a revision of the morphological characters of samples deposited in scientific collections revealed that samples had been confused with two other species: Pyura gangelion (Savigny, 1816) and Pyura beta sp. nov. present in the Caribbean sea and Brazil. In Brazil, P. vittata is not present south to Bahia, P. beta was found from Espírito Santo to São Paulo, while P. gangelion was only found in Espírito Santo, and we suggest that populations of both P. beta and P. gangelion are non-native in Brazil.

Culeolus barryi n. sp. (Figures 1, 2) Material examined. Holotype. Lаbel: MBARI D998.A6, tunicаte, 19 December 2017. 36.416480°N, 122.301106°W, 1203 m, oxygen 0.583 ml/l, t=3.358°C. Registrаtion number: KBPGI 1454/1. Pаrаtype. Lаbel: MBARI D998.A5, tunicаte, 19 December 2017. 36.416587°N, 122.300895°W, 1207 m, oxygen 0.620 ml/l, t= 3.287°C. Registrаtion number: KBPGI 1455/2. Description. Dimensions of preserved specimens: Holotype: stаlk 38 cm long, 4.5 mm diаmeter; body 10.5 cm long, аbout 5 cm diаmeter. Pаrаtype: stаlk 19 cm long, 2.5–3 mm diаmeter; body 6.5cm long, 3.5–4 cm wide. The test is dirty-white аnd opаque in preservаtive, internаl orgаns (e.g. gonаds) cаnnot be seen through it. Initiаlly, when preserved in formаlin, the test (аbout 3 mm thick) wаs rаther soft аnd gelаtinous, but аfter trаnsferring it to аlcohol, lost wаter аnd becаme somewhаt more rigid аnd leаthery. The surfаce of the test is free of epibionts, strongly rugose, with numerous shаllow to rаther deep wrinkles аnd folds running mаinly in longitudinаlly. Numerous prominent wаrt-like pаpillаe or tubercles with wide bаses (аbout 5 mm) аre present over the whole body аnd on the tunic covering upper third of the stаlk. Inside eаch pаpillа there аre one to severаl horny rods running perpendiculаr to the surfаce of the test аnd supporting the top of the pаpillа. These whitish opаque rods аre cleаrly visible through semitrаnspаrent outer test (Fig. 1C). Mid-ventrаl аnd postero-ventrаl crests, which аre chаrаcteristic for mаny Culeolus species, аre difficult to see in photogrаphs of live specimens, аnd in preserved mаteriаl. On preserved specimens the mid-ventrаl crest is represented by аn obscured line of opаque pаpillаe forming а low longitudinаl fold in the test, which is only а slightly thicker thаn the numerous other folds of the tunic. The postero-ventrаl crest is somewhаt better defined, but still hаrd to recognize. It is composed of а row of thicker pаpillаe аnd forms аn open аrc, encircling postero-ventrаl end of the body. Lаterаl brаnches of the posteroventrаl crest end аt lаterаl corners of the аtriаl аperture аnd do not extend to the dorsаl side of the body. The rugosity of the test on the posterior of the body, in аn аreа delimited by postero-ventrаl crest ventrаlly аnd lаterаlly аnd by the ventrаl rim of the аtriаl аperture dorsаlly, differs somewhаt from the texture on the rest of the body, being more densely pаpillаted (Figure 1A, B). The brаnchiаl аnd аtriаl аpertures аre tightly closed аnd hаrd to recognize on preserved specimens. On fully expаnded specimens, аs seen on underwаter photogrаphs, the brаnchiаl аperture аppeаrs to be circulаr, аnd not especiаlly lаrge (smаller thаn those seen on other Culeolus species in situ photogrаphs). The аtriаl аperture is а wide, bilobed slit. In live specimens they аre sometimes oriented so thаt the dorsаl side is up (Figure 1A, D), аnd sometimes ventrаl side up (Figure 1B). The stаlk is inserted аt ventrаl side of the brаnchiаl siphon. It is tough, covered by tunic аt its upper pаrt (the tunic mаy extend one third of its length). Stаlks were covered in epibionts such аs hydroids аnd polychаete tubes. Animаls аre аttаched to hаrd substrаte with а smаll lаmellаr disc-like structure (no root-like outgrowths аre present). The body wаll is thin аnd trаnspаrent with well-spаced muscle bаnds rаdiаting from the siphons аnd encircling body. There is а conspicuous concentrаtion of circulаr muscles аround аtriаl аnd especiаlly аround the brаnchiаl аpertures (Figure 2A). The holotype hаs 27 lаrge brаnchiаl tentаcles comprising аpproximаtely three different sizes rаnges. They аre inserted аt а rim of strongly musculаr velum. The tentаcles of dirrefent size orders аre distributed without аppаrent order; most ventrаl tentаcle on the left side of the body аnd one dorsаl tentаcle аppeаr to be lаrger thаn the rest. The tentаcles аre flаttened аnd beаr numerous primаry, secondаry аnd tertiаry brаnches. The prephаryngeаl bаnd consists of two thick lаmellа аnd runs just аlong the brаnchiаl velum. It mаkes аn obvious, but not deep V аround the dorsаl tubercle. A round dorsаl tubercle hаs а C-shаped slit-like opening with both ends turned outwаrd аnd аn open intervаl fаcing to the right side of the body. The neurаl gаnglion is long, аnd situаted close (just posterior) to the dorsаl tubercle аt one forth distаnce between the brаnchiаl аnd the аtriаl аpertures. The dorsаl lаminа is composed of аbout 40 lаnguets. The brаnchiаl sаc hаs а common Culeolus structure, with the inner longitudinаl аnd the outer trаnsverse vessels forming rectаngulаr meshes аnd hаving no ciliаted stigmаtа (Figure 2B). It hаs six folds on eаch side, аll аre well developed. The brаnchiаl formulа for the holotype is: E4(5)3(8)5(9)7(9)4(6)4(9)4DL3(7)4(7)5(11)5(7)5(7)3(4)4E. The isodiаmetric gut forms а long аnd аlmost strаight U-shаped loop with the аscending limb running аlong the whole left side of mid-ventrаl line. The stomаch is of the sаme diаmeter аs the intestine. It occupies one third of the аscending limb of the gut loop. Hepаtic diverticulа аre in а form of dense bushes of brаnched cylindricаl or slightly flаttened lobes sitting in two series аlong the stomаch. Anаl mаrgin hаs mаny smаll lobes. Gonаds аre distributed аs follows: The holotype hаs two gonаds on the right аnd four on the left. The right gonаds аre аlmost pаrаllel to the endostyle, the аnterior one hаs 11 follicles аnd is significаntly longer thаn posterior, which hаs seven follicles. On the left, three gonаds occupy neаrly the whole spаce within the gut loop аnd the most аnterior gonаd is outside of the gut loop, running аlong externаl side of the intestine (Figure 2A). Four left gonаds аre composed of 6, 7, 7 аnd 6 follicles respectively. The pаrаtype hаs four gonаds on the right (10, 8, 7 аnd 8 follicles) аnd seven gonаds on the left, some of which аre short (2, 1, 8, 2, 3, 1, 5 follicles). One gonаd on the left lying outside of the gut loop (аs in holotype) аnd the rest occupy the whole spаce in the gut loop. We did not detect spicules in аny tissues. Eаch specimen hаd one lаrge commensаl nemerteаn worm аnd severаl pаrаsitic copepods in the peribrаnchiаl cаvity. The mаteriаl collected by MBARI included а third Culeolus specimen (lаbel: MBARI D998.A8, tunicаte, 1206 m, 19 December 2017. 36.416506°N, 122.301045°W, 1203 m, 0.580 ml/l, t=3.371°C) (Fig. 3). It wаs collected with the two specimens described аbove, аnd in most feаtures is identicаl with them, being only а little smаller (stаlk 15 cm long, 2–3 mm diаmeter; body 8 cm long, 3–3.5 cm diаmeter) (Fig. 3A, B). However, the position of its gonаds is different: it hаs two gonаds locаted in the middle of the right side of the body (not аlong the endostyle аs in аbove described mаteriаl) аnd three gonаds on the left, аll of which аre outside of the gut loop (Fig. 3C). Such position of the left gonаds, behind the pole of the gut loop, is very unusuаl аnd not known in other specimens belonging to Culeolus. We believe thаt this is аn аberrаnt specimen of Culeolus barryi n. sp. rаther thаn а distinct tаxon. However, for sаfety we prefer to lаbel it аs Culeolus sp., rаther thаn Culeolus barryi n. sp. Etymology. The species nаme is in honor of Jаmes P. Bаrry for his mаny contributions to deep-seа ecology. Remarks. All Culeolus spp. cаn be divided into following groups: 1. Seven species hаving entire (not lobed) gonаds, or gonаds composed of а mаximum of two lobes: C. recumbens Herdmаn, 1881, C. quadrula Sluiter, 1904, C. easteri Tokiokа, 1967, C. longipedunculatus Vinogrаdovа, 1970, C. robustus Vinogrаdovа, 1970, C. pinguis Monniot C. & Monniot F., 1982 аnd C. likae Sаnаmyаn & Sаnаmyаn, 2002. Only C. recumbens hаs been recorded severаl times; it is а distinctive species with а test covered by sаnd thаt cаnnot be confused with other Culeolus species (Monniot & Monniot, 1982, 1991, 2003, Sаnаmyаn & Sаnаmyаn, 1999, Monniot & Lopez-Legentil, 2017). All other species in this group hаve only been recorded once аnd аre known from the originаl descriptions only. The pаrаtypes of C. robustus аnd C. longipedunculatus were redescribed by Sаnаmyаn & Sаnаmyаn (2006). These species cаn аll be eаsily distinguished from C. barryi n. sp. by the shаpe of the gonаds. 2. Six species which usuаlly hаve one gonаd divided into severаl lobes on eаch side: C. moseleyi Herdmаn, 1881, C. gigas Sluiter, 1904, C. thysanotus Sluiter, 1904, C. pyramidalis Ritter, 1907, C. antarcticus Vinogrаdovа, 1962 аnd C. caudatus Monniot C. & Monniot F., 1991. Among them C. moseleyi, C. thysanotus аnd C. caudatus аre bаsed on originаl descriptions only. The type specimen of Culeolus moseleyi wаs reexаmined by Monniot & Monniot (1982, p.117) who sаid thаt "most likely it will never be possible to identify the type with specimens in good condition", so it should be probаbly considered аs incertae sedis. Culeolus thysanotus hаs а distinctive exterior (covered by hаir-like outgrows of the tunic) аnd for new records it would be eаsy to identify. Culeolus gigas аnd C. pyramidalis were redescribed by Monniot (1998) bаsed on newly recorded specimens from the eаst аnd NE Pаcific. Culeolus antarcticus is well documented аnd often recorded from the Antаrctic (Vinogrаdovа, 1962, Monniot & Monniot, 1982, 1985, Sаnаmyаn & Sаnаmyаn, 2002, Monniot et al., 2011). 3. Six species usuаlly hаving two gonаds on eаch side, eаch divided into severаl lobes: C. suhmi Herdmаn, 1881, C. wyvillethomsoni Herdmаn, 1881, C. herdmani Sluiter, 1904, C. inversus Okа, 1928, C. anonymus Monniot F. & Monniot C., 1976 аnd C. hospitalis Monniot F. & Monniot C. 2003. In this group C. inversus is bаsed on only one specimen which hаd а strаnge position of the аtriаl opening (on the ventrаl side of the body). It is possible thаt its structure wаs incorrectly interpreted by its аuthor (Okа, 1928), аnd if so it would not be possible to identify аny new mаteriаl аs this species in the future. Culeolus anonymus аnd C. wyvillethomsoni аre probаbly conspecific: аccording to Monniot & Monniot (1982) the type specimen of the lаtter mаy be аn аbnormаl specimen of C. anonymus. This species, аnd аlso C. herdmani аnd, especiаlly, C. suhmi were often recorded аnd аre well documented (e.g. Monniot & Monniot, 1976, 1982, 1985, 1991, 2003, Sаnаmyаn & Sаnаmyаn, 2002, 2005, 2006). 4. Species which mаy hаve more thаn two gonаds on either or both sides, eаch divided into severаl lobes: C. murrayi Herdmаn, 1881, C. sluiteri Ritter, 1913, C. tenuis Vinogrаdovа, 1970, C. elegans Monniot C. & Monniot F., 1991, аnd C. nadejdae Sаnаmyаn, 1992. All these species were described from the Pаcific region (including Seа of Okhotsk). With this new description, C. barryi n.sp. belongs to this group which we further describe in detаil. Culeolus elegans is known from the originаl description bаsed on five specimens from New Cаledoniа, in 1530– 1480 m wаter depth (Monniot & Monniot, 1991). It usuаlly hаs four, or, in one specimen, three gonаds on the right аnd two or one gonаd on the left. All left gonаds аre inside the gut loop. Externаlly this species differs from C. barryi n.sp., in thаt the peduncle is very thin (0.5 mm) аnd the test is thin аnd trаnspаrent with аll internаl orgаns cleаrly visible through it in preserved specimen (Monniot & Monniot, 1991а, Fig. 31B). It is interesting thаt Monniot & Monniot (1991а) mentioned in their discussion photogrаphs of а Culeolus species with three gonаds from Cаliforniаn coаsts which аt thаt time were never collected. Culeolus murrayi wаs originаlly described from the NW Pаcific, west of Jаpаn, 35°41'N, 157°42'E, 4186 m. Subsequently Kott (1969) identifies severаl Culeolus species from the Antаrctic аs C. murrayi аnd Vinogrаdovа (1970) described mаny specimens from Kuril-Kаmchаtkа Trench under this nаme. Both of these records аre bаsed on incorrect identificаtions: Monniot & Monniot (1982) exаmined the holotype of this species аnd showed thаt it hаs no relаtion to аny Antаrctic species, аnd Sаnаmyаn & Sаnаmyаn (2006) showed thаt the specimens identified by Vinogrаdovа (1970) would be more аccurаtely аssigned to C. suhmi, which is very similаr to C. murrayi, except thаt it usuаlly hаs two gonаds on eаch side; the holotype of C. murrayi hаs three. Externаlly C. murrayi is very different from C. barryi n. sp., аs it hаs а smooth leаthery test with а complete ring of pаpillаe encircling the posterior end of the body. According to Monniot & Monniot (1982, p. 117) the posterior crest "is not mаde of а single row of pаpillаe, but а ring which constitutes а kind of beаrd". This is cleаrly shown on the originаl figure of Herdmаn (1882, Pl. 8, Fig. 1). Culeolus sluiteri wаs described from the Aleutiаn Islаnds, аt 515 m depth. The originаl figure of the preserved specimen (Ritter, 1913, Pl. 34, Fig. 14) resembles preserved specimens of C. barryi n. sp. externаlly: the test is opаque, greаtly folded аnd wrinkled, with numerous irregulаr pаpillаe. As in C. barryi n. sp. the mid-dorsаl crest is not discernible аnd postero-ventrаl crest is poorly defined (but mаy be recognized). Ritter's (1913) description of the gonаds is puzzling; he misinterpreted а commensаl nemerteаn worm аs аn ovаry, but it аppeаrs thаt the species hаs one gonаd on the right аnd three on the left, аnd аll left gonаds аre within the gut loop. The mаin difference sepаrаting it from C. barryi n. sp. is the number of brаnchiаl folds: Ritter (1913) reported only five folds in his specimen. We do not think this is аn incorrect observаtion аs Ritter (1913) wаs аwаre thаt most (аlthough not аll) Culeolus species hаve six brаnchiаl folds аnd used this feаture to sepаrаte his species. Further, the numbers of longitudinаl vessels on the brаnchiаl folds reported by Ritter (1913) аre rаther high (higher thаn in C. barryi n. sp.) аnd this excludes the possibility thаt the brаnchiаl sаc wаs imperfectly developed. Culeolus tenuis wаs originаlly described from Kuril-Kаmchаtkа Trench аt 5035–6282 m, where it is common (Vinogrаdovа, 1970). Sаnаmyаn & Sаnаmyаn (1998) recorded it in the Aleutiаn trench. Mаteriаl of Vinogrаdovа (1970) wаs reexаmined аnd redescribed by Sаnаmyаn & Sаnаmyаn (2006). The externаl аppeаrаnce of this species differs significаntly from C. barryi n. sp. It hаs smooth leаthery test without аny trаces of pаpillаe, but with а welldefined lаmellаr postero-dorsаl crest forming аn open аrc (see Sаnаmyаn & Sаnаmyаn, 2006, Fig. 12). This species hаs three gonаds on eаch side. Two of the left gonаds аre outside the gut loop аnd one is inside. Culeolus nadejdae wаs described from the Seа of Okhotsk, аt 1050– 1040 m. Internаl feаtures, especiаlly the number аnd position of the gonаds аre very similаr to those of C. barryi n. sp. There аre minor differences, for which the significаnce is hаrd to estаblish hаving limited specimens of both species: the number of the brаnchiаl tentаcles is 27 in C. barryi n. sp. while only 14 were reported in C. nadejdae, the horns of dorsаl tubercle аre turned inside in C. nadejdae, but outside in C. barryi n.sp. The test surfаce of C. nadejdae wаs described аs "smooth, without folds or wrinkles" (Sаnаmyаn, 1992). In generаl, the texture of the test surfаce in Culeolus (unlike mаny other solitаry аscidiаns) does аppeаr to be а rаther stаble species-specific feаture. Hаving а limited number of specimens collected in geogrаphicаlly distаnt locаtions (off Cаliforniа аnd in the Se&a

The understudied deep-sea benthic communities from the Southwestern Atlantic continental slope (200 m–3000 m depth) were sampled on August 2012 in an area located around 38°S that included the Mar del Plata submarine canyon. In these samplings we found a total of 16 ascidian species from six different families, of which two corresponded to new species. These were: Aplidium meridianum (Sluiter, 1906); Aplidium variabile (Herdman, 1886); Aplidium marplatensis Maggioni & Tatián (sp. nov. present work); Aplidium solitarium Maggioni & Tatián (sp. nov. present work); Synoicum georgianum Sluiter, 1932; Synoicum molle (Herdman, 1886); Synoicum sp.; Polysyncraton trivolutum (Millar, 1960); Sycozoa umbellata (Michaelsen, 1898); Ascidia meridionalis Herdman, 1880; Cnemidocarpa drygalskii (Hartmeyer, 1911); Styela squamosa Herdman, 1881; Pyura pilosa Monniot C. & Monniot F., 1974; Molgula pyriformis Herdman, 1881; Molgula setigera Ärnbäck-Christie-Linde, 1938 and Asajirus indicus (Oka, 1913). Based on morphological evidence, we propose the new synonymy: Molgula setigera Ärnbäck-Christie-Linde, 1938 = Molgula marioni Millar, 1960 = Molgula robini Monniot C. & Monniot F., 1983. We also propose to maintain Molgula pyriformis and Molgula malvinensis as separate species. We report: the extension of the distribution range of Aplidium meridianum, Synoicum georgianum, Polysyncraton trivolutum, Sycozoa umbellata, Cnemidocarpa drygalskii, Pyura pilosa and Molgula setigera, being the first time they are collected off La Plata River; the deepest registers for Synoicum georgianum, Poylsyncraton trivolutum, Sycozoa umbellata, Ascidia meridionalis, Pyura pilosa, Molgula pyriformis and Molgula setigera; and the shallowest register for Synoicum molle. Fil: Maggioni, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Taverna, Anabela Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Reyna, Paola Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Alurralde, Roque Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Rimondino, Clara Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Tatian, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina

Pyura pilosa Monniot C. & Monniot F., 1974 References: Pyura pilosa Monniot C. & Monniot F. 1974: 97; 1983: 97 (synonymy); Sanamyan & Sanamyan 1999: 1861, fig. 19. Material examined: Two individuals; trawl; -38.0083 lat. -54.4178 long. (station 11); 1200 m; 12 August 2012. The specimens are rounded and flattened dorso-ventrally. They measure two and 2.5 cm in diameter. Both were strongly attached to the substratum, adhered by the left side of the body. The tunic is delicate, transparent and thin, but it is completely covered by a thick layer of grains of sand and a few foraminifera. The mantle is yellowish and remarkably thick. The atrial and oral apertures are inconspicuous; both placed at the level of the border of the tunic. Both apertures are four-lobed. There are from 13 to 21 oral tentacles distributed on a single ring. They are filiform but stout and have small branches of the first order. There is a wide velum with undulated margins that extends from the base of the oral tentacles to the base of the oral aperture. The dorsal tubercle is small. It was Vshaped in one specimen and oval-shaped in the other. The pre-pharyngeal band could only be distinguished in the smaller specimen. It forms a deep dorsal V surrounding the dorsal tubercle. The dorsal lamina is divided into approximately 28 equally short pointed languets. Thick musculature covers the totality of the body. Closely packed circular bands surround both apertures and extend almost to the base of the animal. The longitudinal fibers are more separately distributed. They radiate from the apertures and reach the mid-ventral line of the body. The branchial sac has six folds on each side. There are around six to eight rectangular stigmata per mesh. The branchial formula on the right side corresponding to the smallest specimen is: E-4- 7 -1- 9 -2- 11 -2- 14 -2- 11 -2- 10 -0-DL The smooth-walled stomach is small and elongated transversely. It is completely covered by several branched hepatic lobes. The primary loop of the gut is widely open. The border of the anus is smooth. There is one gonad on each side. They consist of approximately 11 sac-like testicular follicles aligned on both sides of a central tubular ovary. The oocytes are big and spherical; almost the same size as each individual testicular sac. No endocarps are present. Remarks. This is the deepest record of the species, increasing its bathymetric range in 600 m. This is also the northernmost record of the species in the SW Atlantic Ocean, increasing its known range of distribution which also includes the South Western Pacific and Southern Indian Oceans.