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A colonial ascidian of the genus Distaplia caused a mass mortality of the pen shell Atrina maura (Sowerby, 1835) during June 2016 in the southwest of the Gulf of California (Mexico), with a significant socio-economic cost. Tentatively identified in previous works as Distaplia cf. stylifera, a precise taxonomic determination was still lacking. In the present work, based on a detailed morphological study, it is confirmed that this aggressive species is Distaplia stylifera (Kowalevsky, 1874). Originally described from the Red Sea, the species currently has a wide circumtropical distribution (with the exception of the Eastern Pacific to date) and is reported as introduced in parts of its range. The present account thus represents an important range extension of this species. However, when revising the original description and later observations, the reported variability of several characters makes it likely that the binomen is in fact a complex of species, as is common in other ascidians with wide distributions. A complete morphological and genetic study including populations from the entire range of distribution would be necessary to settle the status of D. stylifera. Taxonomic uncertainties hinder a correct interpretation of biogeographical patterns and inference on the origin of the studied population. Nevertheless, the known introduction potential of the species, coupled with an explosive growth in an anthropized environment, and the lack of any previous reports in the Eastern Pacific, strongly suggest that the investigated population represents yet another instance of ascidian introduction. From the point of view of management, its invasive behavior is cause for great concern and warrants mitigation measures.

Pharyngodictyon melanesius sp. nov. Figure 2 Etymology: from Melanesia Stations: SPANBIOS: DW 5227: 1 specimen. DW 5228: 2 specimens designated as syntypes (MNHN IT-2018- 77 Paris, France). The colonies are composed of a spherical head above a long thin peduncle (Fig. 2A). The tunic is soft, translucent, without sand. The heads are 4 to 5mm in diameter; the longest peduncle is 30mm. The thoraces and abdomens are included in the head and the post-abdomens with gonads extend into the peduncle. The body wall has muscular fibres in a sphincter at the siphons and a few longitudinal fibres on the thorax. On one zooid two lips can be seen on each aperture. The oral tentacles are thin and numerous but could not be counted. The dorsal tubercle is button-like. The triangular dorsal languets are erect between seven to nine transverse branchial bars (Fig. 2B,C). The digestive loop forms a right angle with the thorax. The stomach is short and its wall could not be clearly seen. The post-abdomen extends the entire length of the peduncle with the gonads in a long mass in the anterior part. One larva 0.8mm in diameter was found in the colony head (Fig. 2D). Two sensitive organs are present as black spots. There are three adhesive papillae in a line each separated by a median protrusion with four round papillae on each larval side (Fig. 2D). This larva obviously differs from those of other Pharyngodictyon species recorded from the New Caledonian area: P. magnifili has similar colonies and zooids but a different larva. P. bisinus Monniot C. & Monniot F., 1991 has club-shaped sandy colonies but zooids with only two transverse branchial bars. P. cauliformis MonniotC. & Monniot F., 1991 differs by its large sandy ramified colony on a stout peduncle and a larva of three adhesive papillae circled by a ring of digitate vesicles. P. elongatum Millar, 1982 from New Zealand with club-shaped colonies has a naked tunic and the branchial tissue has three transverse bars. P. mirabile Herdman, 1886 from the Antarctic Ocean is bare, club-shaped with five transverse branchial bars according to Millar (1982) who examined the type and Monniot C. & Monniot F. (1985). P. reductum Sluiter, 1906 represents a sessile unique specimen collected on a beach which likely does not belong to the genus Pharyngodictyon., 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 204-205, DOI: 10.11646/zootaxa.5195.3.1, http://zenodo.org/record/7187776, {"references":["Millar, R. H. (1982) The marine fauna of New Zealand: Ascidiacea. Memoirs of the New Zealand Oceanographic Institute, 85, 1 - 117","Herdman, W. A. (1886) Report on the Tunicata collected during the voyage of H. M. S. Challenger during the years 1873 - 1876; part II; Ascidiae compositae. Report of the Voyage Challenger, 14, 1 - 429.","Sluiter, C. P. (1906) Tuniciers in: Expedition Antarctique Francaise (1903 - 1905) commandee par le Dr. Charcot. Masson & Cie, Paris, 150 pp."]}

Pharyngodictyon magnifili Monniot C. & Monniot F., 1991 Figure 1 Stations: SPANBIOS: CP 5217: 4 specimens. CP 5237: 1 specimen. The largest specimen has a spherical head 15mm in diameter on a narrow peduncle 20mm long (Fig. 1A). The tunic is vitreous with some encrusted sand. The apertures cannot be seen, and all zooids are contracted. Thoraces and abdomens are located in the head and the long post-abdomens extend inside the peduncle. The oral tentacles are thin, long, protruding out of the siphon (Fig. 1B). The branchial tissue has at least seven transverse bars with triangular dorsal languets. The stomach is elongated with longitudinal folds (Fig. 1B). The ovary is anterior to a clump of testis lobes. In one zooid two immature embryos are incubated in the thoracic cavity (Fig. 1B). One tadpole (Fig. 1C) was found free inside the colony head. It has three adhesive papillae in a line circled by very numerous ramified vesicles (Fig. 1C). Sensitive organs cannot be clearly seen. All characters of the SPANBIOS specimens well correspond to those already described from New Caledonia and figured in Monniot C. & Monniot F. 1991 (Figs 7F; 10)., 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 203-204, DOI: 10.11646/zootaxa.5195.3.1, http://zenodo.org/record/7187776

Allorecognition, the ability to distinguish self or kin from unrelated conspecifics, plays several important biological roles in invertebrate animals. Two of these roles include negotiating limited benthic space for colonial invertebrates, and inbreeding avoidance through self-incompatibility systems. Subphylum Tunicata (Phylum Chordata), the sister group to the vertebrates, is a promising group in which to study allorecognition. Coloniality has evolved many times independently in the tunicates, and the best known invertebrate self-incompatibility systems are in tunicates. Recent phylogenomic studies have coalesced around a phylogeny of the Tunicata as well as the Order Stolidobranchia within the Tunicata, providing a path forward for the study of allorecognition in this group.

This study is the first inventory of ascidians from shallow waters (0–25 m) of coastal and reef habitats in the southern Gulf of Mexico where ascidian diversity is poorly known. Sampled environments in 14 locations (38 sites) with 134 samples collected from 2015 to 2017 included coral reefs, coastal lagoons, mangroves, seagrass, ports, and artificial platforms. The 31 identified species comprise 19 genera and 13 families. Ten species are newly reported in the Gulf of Mexico:AscidiapanamensisBonnet & Rocha, 2011;Ecteinascidiastyeloides(Traustedt, 1882);CystodytesroseolusHartmeyer, 1912; Eudistomaaff.amanitum Paiva & Rocha, 2018;EudistomarecifenseMillar, 1977;EuherdmaniafasciculataMonniot, 1983; Euherdmaniaaff.vitrea Millar, 1961;Polycarpacartilaginea(Sluiter, 1885);Botrylloidesmagnicoecum(Hartmeyer, 1912) andDidemnumgranulatumTokioka, 1954. Two new species will be described separately (Clavelinasp. andPyurasp.). This study provides the first records for 26 species ascidians for the region as well as describes increased distributions of ten Atlantic species. Thus, our data provide a starting point for future ecological, experimental and taxonomic studies of ascidians of the Gulf of Mexico.

Aplidium benhami (Brewin, 1946) (Figure 6d) Aplidium (Amaroucium) benhami Brewin, 1946: 95–97, fig. 4, pl. 2, figs 1, 4, pl. 3, fig. 3, pl. 5, fig. 1. Amaroucium benhami Brewin, 1956: 122; 1958a: 439; 1960: 119. Material examined New records. NEW ZEALAND, Bluff Harbour, Tiwai Point (46°35.52 ʹ S, 168°21.14 ʹ E, wharf pile, coll. M. Page, 9 m, 20 August 2007, NIWA68101); Tiwai Point (46°35.51 ʹ S, 168° 21.15 ʹ E), wharf pile, coll. L. Peacock, 6 m, 10 February 2011, NIWA84207. Previously recorded. New Zealand, South Island; Portobello Peninsula (Brewin 1946); Chatham Islands (Brewin 1956); Stewart Island (Brewin 1958a); Cook Strait (Brewin 1960); Fiordland (Page et al. 2014). Description Colonies of Aplidium benhami collected off wharf piles in Bluff Harbour are relatively large, compared to specimens sampled from natural substrata in more exposed environments. They are bright orange (5YR12), cushion-shaped, firm gelatinous colonies measuring up to 100 mm in greatest diameter. The branchial apertures of the zooids are pigmented white, standing out against bright orange thoraces, and a lightly pigmented orange test (Figure 6d). Unlike the small colonies from other regions, the zooids are arranged in parallel rather than stellate systems, and common cloacal apertures are not obvious. The zooids are stout, measuring 7 mm total length, with a thorax and abdomen of approximately equal length and a post-abdomen 3 mm long. The branchial aperture has low indistinct lobes, and the small atrial aperture is surmounted by 3 short atrial lappets. Three embryos are sequentially developed in the atrial brood pouch. The larval characters are as described in Page et al. (2014). Also noted in the present specimen is the orange pigmentation of the branchial sac. Remarks The Tiwai Point A. benhami colonies closely resemble the Otago Harbour holotype in colour and zooid morphology (Brewin 1946). Furthermore, larval characters are the same for this species as described from Fiordland (Page et al. 2014)., Published as part of Page, M. J., 2018, Colonial ascidians from the Foveaux Strait region of New Zealand, pp. 1157-1180 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 52 (17 - 20) on pages 1171-1172, DOI: 10.1080/00222933.2018.1450903, http://zenodo.org/record/5174607, {"references":["Brewin BI. 1946. Ascidians in the vicinity of the Portobello Marine Biological Station, Otago Harbour. Trans Proc N Z Inst. 76: 87 - 131.","Brewin BI. 1956. Ascidians from the Chatham Islands and the Chatham Rise. Trans Proc Roy Soc N Z. 84: 121 - 137.","Brewin BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Roy Soc N Z. 85: 439 - 453.","Brewin BI. 1960. Ascidians of New Zealand. Part XIII. Ascidians of the Cook Strait region. Trans Proc Roy Soc N Z. 88: 119 - 120.","Page M, Willis T, Handley S. 2014. The colonial ascidian fauna of Fiordland, New Zealand with a description of two new species. J Nat Hist. 48: 1653 - 1688."]}

Polyclinum novaezelandiae Brewin, 1958a (Figures 6b, 7a–c) Polyclinum novaezelandiae Brewin, 1958a: 442; Millar 1982: 43. Material examined New records. NEW ZEALAND, Bluff Harbour, Tiwai Point (46.591°S, 168.349°E, 10 m, 31 August 2007, NIWA68097, 1 colony; 46.591°S, 168.349°E, 6 m and 7 February 2011, NIWA87159, 2 colonies). Previously recorded. New Zealand, Foveaux Strait (Brewin 1958a). Description Colonies of this species are large hemispherical cushions reaching 100 mm in greatest diameter and 50 mm high, attached to the substratum by most of their base. Numerous relatively tall (3 mm long), cone-shaped common cloacal apertures are irregularly spaced among crowded zooid branchial apertures, showing no apparent arrangement into regular systems (Figure 6b). The outer test is sparsely covered with fine sand and the colonies have a sky-blue test (5BG8/2), which is apparent on the rims on the branchial apertures. Internally, the test is transparent and gelatinous, containing few sand grains. Large zooids are crowded in the test. The thorax is 4 mm long and has a short branchial aperture with 6 low, well-defined lobes. The atrial aperture is small, muscular and separate from the long atrial languet (Figure 7a). Thirteen longitudinal muscles run on each side from the branchial aperture to the dorsal side of the body wall. The branchial sac has 17–19 rows of 16–18 stigmata per half-row. Ten papillae were counted on each transverse vessel (Figure 7b). The abdomen is short (2 mm long),and the gut is twisted to the left forming a horizontal loop posterior to the throax. A bilobate anus opens in the peribranchial cavity adjacent to the sixth row of stigmata. A relatively long pyriform post-abdomen (6 mm long) contains up to 25 testis follicles posterior to several developing ova (Figure 7c). No larvae were present in colonies examined in this study. Remarks The colony and zooid morphology of specimens collected from Bluff agree closely with the type species from Foveaux Strait described by Brewin (1958a). The in-situ image of the colony (Figure 6B) shows large, scattered common cloacal apertures with raised rims, which collapse on removal from water and are not evident in preserved specimens. The zooids of Polyclinum novaezelandiae are distinguished from 3 other species of Polyclinum endemic to New Zealand – P. sluiteri Brewin, 1956, P. michaelseni Brewin, 1956 and P. cerebrale Michaelsen, 1924 – by a greater number of rows of stigmata in the branchial sac. Furthermore, the colonies of the former 2 species are stalked, while those of P. cerebrale are cushion-shaped with a network of conspicuous sinuous ridges (Millar 1982), unlike the morphology of P. novaezelandiae specimens collected from Bluff., Published as part of Page, M. J., 2018, Colonial ascidians from the Foveaux Strait region of New Zealand, pp. 1157-1180 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 52 (17 - 20) on page 1170, DOI: 10.1080/00222933.2018.1450903, http://zenodo.org/record/5174607, {"references":["Brewin BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Roy Soc N Z. 85: 439 - 453.","Millar RH. 1982. The marine fauna of New Zealand: Ascidiacea. New Zealand Oceanographic Memoir. 85: 114.","Brewin BI. 1956. Ascidians from the Chatham Islands and the Chatham Rise. Trans Proc Roy Soc N Z. 84: 121 - 137.","Michaelsen W. 1924. Ascidiae Krikobranchiae von Nueseeland den Chatham- und den Auckland- Inseln. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i KObenhavn. 77: 263 - 434."]}

Synoicum stewartense (Michaelsen, 1924) (Figure 6c) Macroclinum stewartense Michaelsen, 1924: 413–421, figs 26, 27, 28. Synoicum stewartense: Millar, 1982: 15, fig. 3. Material examined New records. NEW ZEALAND, Stewart Island, Bob’ s Point (41° 51.25 ʹ S, 168° 07.57 ʹ E, 15 m, 31 August 2007, NIWA68089). Previously recorded. Stewart Island, 35 fathoms Michaelsen 1924); in dredged material off Stewart Island (Brewin 1958a); Chatham Rise (Millar 1982); Fiordland (Page et al. 2014). Description Closely spaced, flat-topped, sand-encrusted heads 10–15 mm in diameter, each with 15–18 zooids arranged in a circle around a central, raised common cloacal aperture (Figure 6c). Zooids are large and pigmented red, with internal structures as described in Page et al. (2014). Remarks The central, raised common cloacal aperture, depressed branchial apertures of zooids in a circular system and a low raised rim around the anterior of each colony lobe are consistent with characters for this species described by Michaelsen (1924) and Millar (1982). Adherent sand covers the purple zooids., Published as part of Page, M. J., 2018, Colonial ascidians from the Foveaux Strait region of New Zealand, pp. 1157-1180 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 52 (17 - 20) on page 1171, DOI: 10.1080/00222933.2018.1450903, http://zenodo.org/record/5174607, {"references":["Michaelsen W. 1924. Ascidiae Krikobranchiae von Nueseeland den Chatham- und den Auckland- Inseln. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i KObenhavn. 77: 263 - 434.","Millar RH. 1982. The marine fauna of New Zealand: Ascidiacea. New Zealand Oceanographic Memoir. 85: 114.","Brewin BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Roy Soc N Z. 85: 439 - 453.","Page M, Willis T, Handley S. 2014. The colonial ascidian fauna of Fiordland, New Zealand with a description of two new species. J Nat Hist. 48: 1653 - 1688."]}

Pseudodistoma cereum Michaelsen, 1924 (Figure 9b) Pseudodistoma cereum Michaelsen, 1924: 364–374, fig. 17. Brewin, 1958a: 444–445, fig. 1C 1, C 2, C 3, C 4. Kott, 1963: 77; 1972a: 12–13; 1972b: 173., Published as part of Page, M. J., 2018, Colonial ascidians from the Foveaux Strait region of New Zealand, pp. 1157-1180 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 52 (17 - 20) on page 1176, DOI: 10.1080/00222933.2018.1450903, http://zenodo.org/record/5174607, {"references":["Michaelsen W. 1924. Ascidiae Krikobranchiae von Nueseeland den Chatham- und den Auckland- Inseln. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i KObenhavn. 77: 263 - 434.","Brewin BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Roy Soc N Z. 85: 439 - 453.","Kott P. 1963. The ascidians of Australia. IV. Aplousobranchiata Lahille: Polyclinidae Verril (continued). Aust J Marine Freshwater Res. 14: 70 - 118.","Kott P. 1972 a. The ascidians of South Australia I. Spencer Gulf, St. Vincent Gulf and Encounter Bay. Trans Roy Soc South Aust. 96: 1 - 52.","Kott P. 1972 b. The ascidians of South Australia II. Eastern sector of the Great Australian Bight and Investigator Strait. Trans Proc N Z Inst. 96: 165 - 196."]}

Aplidium knoxi (Brewin, 1956) (Figures 6e, 8a–c) Amaroucium knoxi Brewin, 1956: 125–127, fig. 2D 1, D 2. Material examined New records. NEW ZEALAND, Bluff Harbour, Tiwai Point, wharf piles (46.591°S, 168.349°E, 9 m, 21 August 2007, NIWA68091; 46.591°S, 168.349°E, 5 m, 8 November 2012, NIWA68167). Previously recorded. New Zealand, Chatham Islands (Brewin 1956). Description The pink (5R6/10) colony of Aplidium knoxi is approximately 150 mm long, 50 mm wide and 30 mm thick. Common cloacal apertures with thin transparent rims raised 2 mm above the surface occur randomly throughout the colony (Figure 6e). Zooids are evenly distributed throughout the colony with no apparent arrangement in systems. The test is soft, gelatinous and invested with numerous test and granular cells, with some incorporated sediment. The zooids are relatively large and robust, the thorax measures 1.3 mm and abdomen 2.2 mm. The thorax has approximately 12 longitudinal muscles, a branchial aperture with 6 low rounded lobes, and a narrow atrial aperture surmounted by a tripartite lappet (Figure 8a). There are 14 rows of approximately 10 stigmata per half-row in the branchial sac. The barrel-shaped stomach has 24 folds, some of which are discontinuous. There is a wide intestinal tract ending in a bilobate anus. The post-abdomen is long (6.4 mm) with fine muscles evenly spaced along the entire length. Numerous testis follicles are in 2 irregular rows occupying the posterior half of the post-abdomen with developing ova anterior to the testis follicles (Figure 8b). A large convoluted vas deferens runs ¾ of the length of the post-abdomen. Larvae were present in zooids from a colony collected in late spring 2012 (NIWA68167). They have a robust 1.5 mm long trunk with 3 adhesive organs and 3 stout median ampullae. The anterior end of the trunk is covered by an arc of epidermal vesicles each side of the midline (Figure 8c). Remarks The colony size and colour, and arrangement of zooids, are different from the holotype collected off coastal rocks in the Chatham Islands by Brewin (1956). The morphology of the zooids is, however, the same as in our specimen. The number of folds of the stomach and rows of stigmata are similar, and both have a tripartite atrial languet, bilobate anus and numerous testis follicles in the lower part of the posterior abdomen, posterior to the ovary. Larvae of this species are newly described here. The variation in colony size and arrangement of zooids is most likely to be a function of exposure to high currents. A similar environmental response is common for Pseudodistoma cereum in Fiordland, where encrusting colonies are found in exposed habitats and massive forms are in deep water (Page et al. 2014)., Published as part of Page, M. J., 2018, Colonial ascidians from the Foveaux Strait region of New Zealand, pp. 1157-1180 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 52 (17 - 20) on pages 1172-1173, DOI: 10.1080/00222933.2018.1450903, http://zenodo.org/record/5174607, {"references":["Brewin BI. 1956. Ascidians from the Chatham Islands and the Chatham Rise. Trans Proc Roy Soc N Z. 84: 121 - 137.","Page M, Willis T, Handley S. 2014. The colonial ascidian fauna of Fiordland, New Zealand with a description of two new species. J Nat Hist. 48: 1653 - 1688."]}

Colonial ascidians, Clavelina elegans (Oka, 1927) and Clavelina miniata Watanabe & Tokioka, 1973 are reported for the first time in Korean waters. As a result of this study, three species of the genus Clavelina are now recorded in Korean fauna. Clavelina elegans and C. miniata have been reported only from Japan. We expanded the distribution range of these species to Korea. The specimens of C. elegans and C. miniata were collected from the subtidal zone of Beomseom and Chagwido in Jeju-do by SCUBA diving. Detailed descriptions, illustrations and photographs of these species are provided in this paper.

Photosymbiotic ascidian fauna were surveyed in the subtidal zone off Pari Island in the Thousand Islands (Java Sea, Indonesia). Nine species were recorded: Didemnum molle, Trididemnum miniatum, Lissoclinum patella, L. punctatum, L. timorense, Diplosoma gumavirens, D. simile, D. simileguwa, and D. virens. All of these species have been previously recorded in the Ryukyu Archipelago, Japan. Diplosoma gumavirens and D. simileguwa were originally described from the Ryukyu Archipelago in 2009 and 2005, respectively, and all of the observed species are potentially widely distributed in Indo-West Pacific coral reefs.

A colonial ascidian, Synoicum clavatum has previously been reported from Japan. Here, we provide detailed descriptions and illustrations of S. clavatum as the first record in Korea. Synoicum clavatum is characterized by club­ shaped colonies with oval head and elongate stalk, circular cloacal systems, a branchial sac with 14-16 stigmata rows of 10-17 stigmata per row and a stomach with smooth surface. The specimens of S. clavatum were collected in the subtidal zone (15-25 m depth) at Beomseom and Mumseom in Jeju­do while SCUBA diving from 2000 to 2014.

During the Spanish expedition CIEMAR 99/00, on board the BIO‐Hesperides, 30 species of ascidians (distributed in 13 genera and eight families) were collected using a rock dredge in the Bransfield and Gerlache straits. Most of them were already known, but one species, Tetrazona ciemari sp. nov., is new for science. Additional morphological data are provided for six species. Five are reported for only the second time and the known distributions of five species are extended.

Trididemnum shawi sp. nov. (Figures 12, 11D) Type material Holotype: NIWA 10872. Type locality: Fiordland, Crayfish Heights, Thompson Sound (45° 14.279’S, 166° 59.566’E, 10 m, 31 February 2006). Paratypes: Fiordland, Crayfish Heights, Thompson Sound (45° 14.279’S, 166° 59.566’E, 10 m, 31 February 2006, NIWA 87166); The Narrows, Long Sound (46° 03.829’S, 166° 44.16’E, 13 m, 28 February 2009 NIWA 49945, one colony); Nine Fathom Passage, Dusky Sound (45° 44.237’S, 166° 53.199’E, 16 m, 1 February 2009, NIWA 49960, one colony); Sunday Cove, Breaksea Sound (45° 35.89S, 166° 44.58’E, 10 m, 18 April 2012, NIWA 68138, 68139, 68140, 68141 and 68142). Etymology Named after Lance Shaw in recognition of his lifetime passion for conservation in Fiordland. Description The colonies of Trididemnum shawi sp. nov. are irregular shaped cushions reaching 150 mm long and 50 mm high. They have large terminal common cloacal apertures (5 mm diameter) located at the proximal end of upright lobes in the colony. The colony is supported by positive hydrostatic pressure and basal test core expanded into the centre of large common cloacal cavities that collapse on removal from water. Colonies are peach coloured (YR 7/8) with characteristic clusters of red pigment cells scattered randomly throughout the test (Figure 11D). The texture is gelatinous with zooids regularly packed around the outside edge and sparse spicules concentrated in a layer around zooid branchial apertures. The inner test below the zooid thoraces has no spicules. Developing larvae are present in the test surrounding posterior abdominal cavities in colonies from Breaksea Sound. The zooids are small, the thoraces measuring 0.45 mm and abdomen 0.8 mm long in contracted specimens. There are reticulated posterior abdominal canals running below a single layer of zooids. The canals connect to a central common cloacal cavity in the anterior half of the colony, the centre supported by an extension of the basal test. The zooid branchial aperture has six sharply pointed lobes, and the atrial aperture is a sessile opening in the centre of the thorax. The branchial sac has three rows of stigmata and a small lateral thoracic organ each side adjacent to the third row of stigmata (Figure 12A). The number and shape of stigmata are difficult to determine due to contraction of the thorax. There is a long retractor muscle originating from the base of the thorax. The gut has a smooth globular stomach and the intestine is wide with constrictions occurring between duodenum, posterior stomach and rectum (Figure 12A). There is a single large dome-shaped testis follicle with a vas deferens tightly coiled 10–11 times anticlockwise (Figure 12B); a large ovum lies on the anterior dorsal side of the testis. Developed larvae in colonies collected in April 2012 from Breaksea Sound (NIWA68138) are large (trunk length 1.1 mm) and have four stout lateral ampullae crowded each side of three slender adhesive papillae (Figure 12C). Zooids in these colonies have no testis, suggesting that the reproductive season has ended, but the brooded larvae are still maturing. Stellate spicules are present in a layer around the zooid thoraces and range in size from Remarks Of nine species of Trididemnum described with sessile atrial openings similar to Trididemnum shawi sp. nov., Trididemnum cyclops Michaelsen, 1921 and T. miniatum Kott, 1977 have only six, and T. nubilum Kott, 1980 seven coils of the vas deferens, compared with 10–11 for T. shawi sp. nov.. Trididemnum paracyclops Kott, 1980 from Australia and the Western Pacific has 10 coils of the vas deferens, but differs markedly in colony (forming thin encrusting colonies), zooid and spicule morphology, a zooid with a long oesophageal neck and larvae with only two adhesive papillae. Trididemnum poma Monniot and Monniot, 2001 from Saipan has a larva with a similar arrangement of adhesive papillae and lateral ampullae, but the larvae are significantly smaller (0.25 mm compared with 1.1 mm) than those of T. shawi sp. nov.. Furthermore, the colonies of T. poma are thin, brittle and encrusting compared with those of T. shawi. Both Trididemnum species recorded from New Zealand, T. sluiteri Brewin, 1958 and T. cerebriforme Hartmeyer, 1913, differ from T. shawi in possessing atrial siphons. Trididemnum shawi sp. nov. is distinguished from the majority of species in this genus by the presence of a sessile transverse atrial opening, a large number of coils of the vas deferens, cushion-shaped colonies with terminal common cloacal apertures and scattered red pigment granules in the tunic., Published as part of Page, M. J., Willis, T. J. & Handley, S. J., 2014, The colonial ascidian fauna of Fiordland, New Zealand, with a description of two new species, pp. 1653-1688 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 48 (27 - 28) on pages 1676-1678, DOI: 10.1080/00222933.2014.896487, http://zenodo.org/record/5193878, {"references":["Michaelsen, W. 1921. Ascidien vom westlichen Indeschen Ozean aus dem Reichmuseum zu Stockholm. Arkiv foer Zoologi. 13: 1 - 25.","Kott, P. 1977 Algal-supporting didemnid ascidians for the Great Barrier Reef. In: Proceedings of the Second International Coral Reef Symposium; Maiami: University of Maiami.","Kott, P. 1980. Algal-bearing didemnid ascidians in the Indo-west Pacific. Memoirs of the Queensland Museum. 20: 1 - 47.","Hartmeyer, R. 1913. Tunicata. In: L Schaltze (ed), Zoologische und Antropologische Ergebnisse einer For schungsreise im Westlichen und Zentrelen Sudafrica ausgefuhrt in den Jaren 1903 - 1905. Bd. 5. Denkschriften der Medizinisch-naturwissenschaftlichen Gesellschaft zu Jena 17: p. 124 - 144."]}

Ritterella sigillinoides (Brewin, 1958) Pesudodistoma sigillinoides Brewin, 1958a: p. 455, fig. 2A 1, A 2, A 3, A 4 Pesudodistoma sigillinoides: Millar 1982: p. 47 Material examined New Records: Edwardson Sound (45° 56.52’S, 166° 37.56’E, 14 m, 29 February 2009, NIWA 49948, three colonies); Caswell Sound (45° 01.01’S, 167° 08.40’E, 18 m, 3 February 2009, NIWA 49989, two colonies). Previously recorded: New Zealand, Stewart Island (Brewin 1958a); east coast Stewart Island, 101 m (Millar 1982). Description The colonies have numerous, small light-yellow capitate heads to 10 mm diameter on slender tapering, almost woody, sometimes branching stalks up to 40 mm high. As many as 20–30 zooids are embedded in a soft gelatinous test and open separately to the surface. The zooids are up to 14 mm long with atrial and branchial siphons that have six low indistinct lobes and a stomach with 11 broken folds. No larvae were present in specimens collected from Fiordland. Remarks This species is relatively uncommon in Fiordland and easily distinguished from other species by soft gelatinous colony heads. The branching character in the specimens collected in Fiordland agrees with the description by Millar (1982) collected from 135 m off Port Pegasus, Stewart Island. Deep emergent species are common in shallow water in Fiordland. The branching character seen in colonies here may be common to individuals in deeper environments., Published as part of Page, M. J., Willis, T. J. & Handley, S. J., 2014, The colonial ascidian fauna of Fiordland, New Zealand, with a description of two new species, pp. 1653-1688 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 48 (27 - 28) on page 1676, DOI: 10.1080/00222933.2014.896487, http://zenodo.org/record/5193878, {"references":["Brewin, BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Royal Soc NZ. 85: 439 - 453.","Millar, RH. 1982. The marine fauna of New Zealand: Ascidiacea. New Zealand Oceanogr Mem. 85: 114 pp."]}

Aplidium benhami (Brewin, 1946) (Figures 9, 7C) Aplidium (Amaroucium) benhami Brewin, 1946: p. 95 –97, fig. 4, pl. 2, figs 1, 4, pl. 3, fig. 3, pl. 5, fig. 1. Amaroucium benhami Brewin, 1956a: p. 122; 1958a: p. 439; 1960: p119. Material examined New records: Thompson Sound, Crayfish heights (45° 13.182’S, 166° 58.656’E, 3–10 m, 30 January.2006, NIWA 49993). Previously recorded: New Zealand, South Island; Portobello Peninsula (Brewin 1946), Chatham Islands (Brewin 1956a), Stewart Island (Brewin 1958a) and Cook Strait (Brewin 1960). Description Aplidium benhami has characteristic small orange vase-shaped colonies arising from a short narrow stalk. The colony heads, approximately 30 mm high, can be joined at their base to form diffuse aggregations in a larger colony (Figure 7C). The hemispherical tops of the colony heads contain up to 60 zooids in a soft, sand-free gelatinous test. The orange zooids form stellate systems around indistinct common cloacal apertures. The rim of zooid branchial apertures is pigmented white and the atrial aperture surmounted by three lappets, the central one being the longest of the three. Zooids measure approximately 9 mm long, and the post-abdomen encompasses half of the total length (Figure 9A). The branchial sac has 11 rows of 12–13 stigmata per half row. The stomach is barrel-shaped with 23–29 discontinuous folds. Testis follicles occur in paired rows in the posterior threequarters of the post-abdomen and the ovary lies above at the anterior end. Bright orange embryos are crowded in the atrial cavity, which is bulged into a brood pouch to accommodate the large larvae, 0.85 mm in trunk length (Figure 9B). The larvae have three slender median ampullae alternating between three adhesive papillae arranged along the median line and four short lateral ampullae each side (Figure 9C). Remarks Fiordland species closely resemble the type specimen from Otago (Brewin 1946) in colour, colony and zooid morphology. However, Brewin did not note the presence of a brood pouch, or show detail of the arrangement of ampullae on lateral and median sides of the tadpole. The 3.4 mm long tadpole measured by Brewin is significantly greater than the trunk length of larvae from our material (0.85 mm). Brewin’ s measurement probably referred to the total larval length. Aplidium larvae are generally less than 1.0 mm trunk length with few exceptions; e.g. Kott (1992) named Aplidium magnilarvum Kott, 1992 after the large 2 mm long larva (trunk length)., Published as part of Page, M. J., Willis, T. J. & Handley, S. J., 2014, The colonial ascidian fauna of Fiordland, New Zealand, with a description of two new species, pp. 1653-1688 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 48 (27 - 28) on pages 1668-1669, DOI: 10.1080/00222933.2014.896487, http://zenodo.org/record/5193878, {"references":["Brewin, BI. 1946. Ascidians in the vicinity of the Portobello Marine Biological Station, Otago Harbour. Trans Proc Royal Soc New Zealand. 76: 87 - 131.","Brewin, BI. 1956 a. Ascidians from the Chatham Islands and the Chatham Rise. Trans Proc Royal Soc New Zealand. 84: 121 - 137.","Brewin, BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Royal Soc NZ. 85: 439 - 453.","Brewin, BI. 1960. Ascidians of New Zealand. Part XIII. Ascidians of the Cook Strait region. Trans Proc Royal Soc New Zealand. 88: 119 - 120.","Kott, P. 1992. The Australian ascidiacea III. Aplousobranchia (2). Memoirs of the Queensland Museum. 32: 375 - 620."]}

Didemnum lithostrotum Brewin, 1956 (Figure 11F) Didemnum lithostrotum Brewin, 1956a: p. 127 –129, figs 3A 1, A 2, A 3. Didemnum lithostrotum: Millar 1982: 49, 51. Material examined New record: Caswell Sound, Paua Bay (45° 01.01’S, 167° 08.40’E, 20 m, 3 February 2009, NIWA 49980, one colony). Previously recorded: New Zealand: Chatham Islands (Brewin 1956a); Chatham Rise (Brewin 1956a); Stewart Island (Brewin 1958a). Description The pink/orange (YR 7/6) colony from Caswell Sound is 1 mm thick, encrusting on the brachiopod Liothyrella neozealandica. The test is divided into irregular polygonal areas, each with a central common cloacal aperture (Figure 11F). Spicules occur throughout the colony, although more are concentrated in a layer near the surface and at the substratum. They have eight rounded rays in optical cross-section and measure 40–70 µm in diameter. The zooids are 1 mm long in fixed material, the branchial aperture is relatively tall with six low pointed lobes, and the atrial aperture is smooth rimmed with a short simple lappet. The stomach is small and globular. There are two testis follicles with six to seven coils of the vas deferens. Remarks Possible synonymy of this species to Didemnum densum (Nott 1892) was mentioned by Millar (1982). We have placed the Fiordland colony in the species Didemnum lithostrotum based on the southern distribution of the holotype, and different morphology of the tunic (not in polygonal pattern in D. densum) and the branchial aperture lobes. The zooids in the current species are smaller than given by Brewin (1956a), but this is because they were contracted on collection and preservation. Didemnum densum in relaxed colonies has a branchial siphon with needle-like lobes whereas D. lithostrotum does not. An in-situ photograph by Stocker (1985) identified as D. densum shows polygonal pattern in the tunic; it could be a misidentification because this is an important character., Published as part of Page, M. J., Willis, T. J. & Handley, S. J., 2014, The colonial ascidian fauna of Fiordland, New Zealand, with a description of two new species, pp. 1653-1688 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 48 (27 - 28) on page 1680, DOI: 10.1080/00222933.2014.896487, http://zenodo.org/record/5193878, {"references":["Brewin, BI. 1956 a. Ascidians from the Chatham Islands and the Chatham Rise. Trans Proc Royal Soc New Zealand. 84: 121 - 137.","Millar, RH. 1982. The marine fauna of New Zealand: Ascidiacea. New Zealand Oceanogr Mem. 85: 114 pp.","Brewin, BI. 1958 a. Ascidians of New Zealand. Part XI. Ascidians of the Stewart Island region. Trans Royal Soc NZ. 85: 439 - 453.","Nott, JT. 1892. On the composite ascidians of the North Shore reef. Trans Proc New Zealand Inst. 24: 305 - 334.","Stocker, LJ. 1985. An identification guide to some common New Zealand ascidians. University of Auckland Leigh Marine Laboratory, Auckland, New Zealand. 74 p."]}

Polycitorella graphicum n. sp. (Figures 23 A,C; 24) Station. TA 51 (MNHN A 3 POL.B 14, holotype). The single colony is a thick crust 6cm in length and 1cm thick (Fig. 23 A). It is made of convoluted lobes protruding from a common base. The walls of the lobes are straight and the surface is flat. The zooids are lined along the outline of the lobes. The oral and atrial openings are projecting with a stellate design above the flat colony surface. The spicules (Fig. 23 C) are dense in the whole colony thickness except a thin layer on the side walls of the lobes. The zooids (Fig. 24 B) are deeply withdrawn into the colony. The largest individuals are 8 to 9mm long. The thoracic musculature is strong extending in 2 ribbons on the abdomen. The branchial sac has 13 rows of stigmata (Fig. 24 A). The stomach has a smooth wall. The intestine shows a bulbous segment before the rectum (Fig. 24 B). The gonads occupy the gut loop. The testis vesicles are poorly developed around a central ovary in this incubatory colony. The larva (Fig. 24 C) 1.9 to 2mm long takes place from the upper part of the abdomen to the basal part of the atrial cavity. It has 3 adhesive papillae and 6 pairs of lateral vesicles. Ocellus and otolith are in a posterior position. The tail encircles the trunk in half a turn. The larval trunk is dense no organs are already differentiated. The spicules (Fig. 23 C) are stellate but irregular, from 20 to 30 ��m of diameter few of them reach 50 ��m. P. graphicum n. sp. essentially differs from other species of the genus having more than 10 stigmata rows by the linear disposition of the zooids at the periphery of the colony, and by the design of the dark pigment cells. It lacks the thick aspicular tunic layer at the colony surface., Published as part of Monniot, Fran��oise, 2012, Some ascidians from the southern coast of Madagascar collected during the " AtimoVatae " survey, pp. 1-42 in Zootaxa 3197 on page 29, DOI: 10.5281/zenodo.246182

Polycitorella peresi Plante & Vasseur, 1966 (Figure 23 B,D) Polycitorella peresi Plante & Vasseur, 1966, Madagascar, Tulear. Station. TA 52 (MNHN A 3 POL.B 13). The colonies are thick hard cushions with a circular or undulated outline, sometimes divided into lobes. The largest colony is 10cm in length and 3cm in thickness. The top surface, without spicules, is glistening, opaque, black (Fig. 23 B) or brown with patches of darker brown pigment spots in formalin. The oral apertures are not arranged in circular systems. The oral and atrial apertures of each individual are close to each other and slightly protruding at the colony surface, but the zooids are deeply withdrawn inside the colony. The zooids are encased in hollows of the tunic which contains densely packed spicules (Fig. 23 D). Both siphons are tubular with 6 lobes. The thoracic musculature is continuous extending in 2 strong ribbons along the abdomen.The branchial sac has 12 or 13 rows of stigmata. At the base of the thorax, on each side and near the endostyle, a circular depression without spicules can be seen remembering the didemnid lateral organs. This structure, difficult to see without staining, is different from the protruding organs described in other Polycitorella, more related to a fold of the body wall. These cup-like spots are also present in some re-examined zooids of two other species of Polycitorella: P. coronaria and P. mariae. The stomach is smooth-walled followed by a narrow tube posteriorly enlarged. A constriction separates the posterior intestine. Numerous testis vesicles and a central ovary occupy the gut loop. No larvae have been found. The spicules (Fig. 23 D) have an average size of 30 to 40 ��m, a few reach 55 ��m. All of them have the same shape in irregular rays with a blunt tip. Remarks. Eight species of Polycitorella have been described. P. hospitiolum (Savigny, 1816) and P. stellifera Monniot & Monniot, 2001, both differ by few stigmata rows. P. setoensis Nishikawa, 1980 has disk-shaped spicules. P. coronaria Monniot F., 1988 has circular systems and up to 20 rows of stigmata. P. orientalis Kott, 1990 has no dark pigment, spicules of 25���35 ��m, 10 rows of stigmata and no circular systems. P. m a r i a e Michaelsen, 1924 from New Zealand lacks dark pigment, lacks circular systems and the spicules are smaller. P. pallida Millar, 1962, with 16 stigmata rows, has no dark pigment. The type specimen of P. p e re s i (MNHN A 3 POL.B 11) consists in small pieces. The colour in life was said to be red. In formalin, the upper layer of the samples is soft and black, the columnar base is white and hard. The zooids are damaged, with about 13 rows of stigmata. The general aspect is the same as in Atimo Vatae samples and the spicules are the same in shape and size. P. p e re s i is only known from Madagascar., Published as part of Monniot, Fran��oise, 2012, Some ascidians from the southern coast of Madagascar collected during the " AtimoVatae " survey, pp. 1-42 in Zootaxa 3197 on pages 29-30, DOI: 10.5281/zenodo.246182, {"references":["Plante, R. & Vasseur, P. (1966) Sur une collection d'ascidies de la region de Tulear (cote sud-ouest de Madagascar). Annales de l'universite de Madagascar, Sciences de la nature et mathematiques, 4, 143 - 152.","Savigny, J. C. (1816) Memoires sur les animaux sans vertebres, Paris 1816, 2, 1 - 239.","Nishikawa, T. (1980) Ascidians from the coast of Kii Peninsula, Middle Japan, with descriptions of two new species. Memoirs of the National Science Museum, 13, 97 - 111.","Monniot, F. (1988) Ascidies de Nouvelle Caledonie. V. Polycitoridae du lagon. Bulletin du Museum National d'Histoire Naturelle, Paris (4), 10 A (2), 197 - 235.","Kott, P. (1990) The Australian Ascidiacea. Part 2, Aplousobranchia (1). Memoirs of the Queensland Museum, 29 (1), 1 - 266.","Michaelsen, W. (1924) Ascidiae krikobranchiae von Neuseeland den Chatham und den Aukland Inseln. Videnskabelige Meddelelser fra Dansk naturistorisk Forening: Kobenhavn, 77, 263 - 434","Millar, R. H. (1962) Further descriptions of South African ascidians. Annals of the South African Museum, 46 (7), 113 - 221."]}

The CH2Cl2-MeOH extract of a South African tunicate described as the new Synoicum globosum Parker-Nance sp. nov. (Ascidiacea, Aplousobranchia) was subjected to 1H NMR-guided fractionation. This resulted in the identification of new 3″-bromorubrolide F (1), 3′-bromorubrolide E (2), 3′-bromorubrolide F (3) and 3′, 3″-dibromorubrolide E (4), and reisolation of known rubrolides E (5) and F (6), based on NMR spectroscopic and mass spectrometric data. Biological testing of both new and known members of this reported antimicrobial family of halogenated, aryl-substituted furanones indicated moderate antibacterial properties for 3′-bromorubrolide E (2), 3′, 3″-dibromorubrolide E (4), and rubrolide F (6) against methicillin-resistant Staphylococcus aureus (MRSA) and S. epidermidis.

We report five alien ascidians with some distinct features that were investigated from August 2009 to October 2011 in Korea, among which Ascidiella aspersa (Müller, 1776) belonging to family Ascidiidae of order Phlebobranchia and Molgula manhattensis (De Kay, 1843) belonging to family Molgulidae of order Stolidobranchia are newly discovered invasive species. These ascidians were identified and their phylogenetic relationships were clarified through molecular analysis using about 680 bp of nuclear 18S rDNA and about 670 bp of mt-COI genes along with detailed morphological characteristics, and reported for the first time in Korea. It was discovered that A. aspersa was widespread three coastlines of Korea except Jeju Island, and M. manhattensis first found in Mokpo, Gunsan, and Incheon in June 2010 extended into Busan of Korea Strait in 2011.

Four aplousobranch ascidians (Aplidium conicum, Polycitor adriaticus, Cystodytes dellechiajei, Eudistoma mucosum) from the northern Adriatic Sea are redescribed. Gonads and larvae of three of them are observed for the first time.

Brevicollus tuberatus Kott, 1990 (figure 3B–D) Brevicollus tuberatus Kott, 1990a: 237. Distribution. New records: New South Wales (inside Lighthouse Reef, Ulladulla, QM G308571). The species previously was known only from the type and paratype, from South Australia and Gabo I. (eastern Victoria) from 10 to 15 m depth. The new record is from 1 to 4 m. Description. The colony is firm and irregular growing around weed stalks. Sand is embedded throughout. Numerous longitudinal muscle bands on the thorax remain separate and do not form a continuous coat. Only a few transverse muscles are beneath the longitudinal ones, which continue in a wide band along each side of the abdomen. In adult zooids five rows of about 35 stigmata per row are present, each crossed by a parastigmatic vessel. Juvenile vegetative zooids have 18–20 stigmata per row. The gut loop is short, the abdomen about the same length as the thorax. The stomach is a relatively small barrel with 12 shallow parallel longitudinal folds about half-way down the gut loop. Gonads are in the loop at the posterior end of the abdomen. The posterior abdominal vascular process is variable in length, but always fine. About five larvae are in the posterior half of the right side of the atrial cavity in these zooids. They have a relatively short but deep trunk as previously described (Kott, 1990a) with two rows of stigmata in the larval pharynx, a long, vertical gut loop, a large yolk mass and the adhesive organs sessile and depressed into the trunk. Remarks. Although a few more stomach folds were counted than in the types, the newly recorded specimen resembles the type material in most significant respects. The presence of parastigmatic vessels and the relatively large zooids are all unusual features of this species, and the larvae are unique. The phylogenetic relationships of this genus are obscure and its assignation to the Polycitoridae is based solely on the separately opening six-lobed apertures and the location of gonads in the gut loop (although the abdomen is relatively short). Parastigmatic vessels do occasionally occur in Holozoidae, but the genus does not have any other affinities with that family (in which there is a pronounced vegetative stolon)., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1625, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Polycitor circes Michaelsen, 1930 Polycitor circes Michaelsen, 1930: 495; Kott, 1990a: 169 and synonymy. Distribution. New records: Western Australia (WAM, Kimberley, Cone Bay). The new record is within the previously known range. See Kott (1990a). Description. This new material extends the known range of morphological variation of both colony and zooids in this species. Colonies are terminal rounded heads on slightly longer, thick, branched stalks (two or three branches) up to 6 cm high. Black pigment is in the surface of the soft, translucent gelatinous test. About 14 longitudinal muscles are on each side of the thorax, 12 rows of about 25 stigmata were detected in the branchial sac, and although the gastric glandular epithelium appears to be in longitudinal tracts, the stomach folds are obscure in some places, tending to flatten out posteriorly. The abdomen in contracted zooids is only about three times the length of the thorax, although when relaxed it is many times longer. The large larvae (trunk 3.0 mm long) begin their development at the top of the oesophageal neck rather than in the thorax. The three adhesive organs are triradially arranged at the anterior end of the trunk. Remarks. The species is readily distinguished from all except P. annulus Kott, 1990a by the dark pigment in the test, long zooids and large larvae with triradially arranged adhesive organs. Although the number of rows of stigmata in these specimens approaches the number in P. annulus, the colony shape and the size of the larvae are different., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1623, DOI: 10.1080/00222930110104258

Eudistoma maculosum Kott, 1990 Eudistoma maculosum Kott, 1990a: 216. Distribution. New records: New South Wales (Summercloud Bay, QM G308504). The species previously has been recorded once only, from New South Wales (see Kott, 1990a)., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1624, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Polycitor emergens Kott, 1990 Polycitor emergens Kott, 1990a: 170; Sanamyan and Sanamyan, 1999: 1841. Distribution. New records: New South Wales (Durras Lake, entrance, QM G308507). The species previously was known only from the type locality off New South Wales (Cronulla) and off Tasmania (Sanamyan and Sanamyan, 1999)., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1624, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Cystodytes philippinensis (Herdman, 1886) (figure 2A–E) Cystodytes philippinensis Herdman, 1886: 140; Tokioka, 1950: 123. Cystodytes hapu Monniot and Monniot, 1987: 64; 2001: 235. Distribution. New records: Queensland (Heron I., QM G308020; Swain Reefs QM G305801). The species previously was known from the western Pacific (Philippines, Herdman, 1886; Palau Is, Tokioka, 1950; Monniot and Monniot, 2001; French Polynesia, Monniot and Monniot, 1987; the Maldives, Monniot and Monniot, 2001). Description. Both living and in preservative one of the colonies (QM G305801) is a hard pearl-grey tongue-shaped slab about 6 mm thick and about 8 cm long. The colour results from the spherical black pigment cells amongst the large globular spicules. The colony from Heron I. (QM G308020) is an even, tough mat about 5 mm thick with its surface divided into white patches (owing to the absence of pigment) separated by a network formed by dark reddish brown pigment mixed with white spicules. The branchial apertures are in the darker areas and the test around the thoraces (the upper part of the colony) also contains dark pigment amongst the spicules. In both colonies globular spicules to 0.09 mm diameter are crowded in the test making it hard and rigid. Parallel, vertical hour glass-shaped compartments for the zooids interrupt the test, the thoraces in the upper half of the colony, and the abdomina in the lower half. The basal half of each compartment is surrounded by a capsule of three or four overlapping layers of saucer-shaped spicules (to 0.5 mm diameter). This capsule is itself surrounded by the crowded globular spicules that occupy the remainder of the test. The saucer-shaped spicules are present only around the abdominal parts of each zooid compartment. In both the newly recorded colonies the upper half of each compartment is empty, the zooids being contracted and withdrawn into the basal (abdominal) half and the abdomen pulled up to the right of the thorax. On the surface of the colony are numerous large common cloacal apertures, each surrounded by three to five branchial apertures (six-lobed). The common cloacal cavities are fairly shallow depressions in the surface, receiving the openings of the atrial siphons which, when distended, presumably fill the spaces in the stiff, rigid test between the thoracic compartments and cloacal cavities. The test over the cloacal cavities is thin and in the preserved specimens lies in the folds around the central aperture. In the living specimen this thin test may be forced up into a short chimney by the excurrent flow of water, probably exposing the whole of the cloacal cavity to the exterior. Zooids are black in life but beige coloured in preservative. Four rows of stigmata are present, although the number in each row was not determined. Both apertures are on short anteriorly directed siphons with six-lobed apertures. The thoracic muscles are mainly longitudinal and they continue on to the abdomen in two strong, wide bands, one along each side of the ventral mid-line. The stomach is smooth-walled, and the gut loop wide. The testis is a circle of about eight club-shaped follicles, the narrow ends converging in the centre of the circle where they join the vas deferens that extends toward the base of the atrial cavity between rectum and stomach and oesophagus. Neither eggs nor larvae were found in either specimen. Remarks. The species is distinguished by its large globular spicules as well as the capsule of saucer-shaped ones. Spicule distribution is variable—the globular spicules crowded throughout the test in the present specimens, although Tokioka (1950) and Herdman (1886) found them only in the abdominal test, around the top of the abdominal capsule. Tokioka (1950) found them to be only 0.04 mm diameter, but of identical form to the variably sized spicules crowded throughout the newly recorded colonies. The larva, incubated in a pouch at the top of the abdomen, has been described for C. hapu Monniot and Monniot, 1987 (see Monniot and Monniot, 2001). This species conforms with the present one in all its significant characters. The oesophageal muscle found in the test of Cystodytes dellachiajei (see Kott, 1990a) has not been observed in the present specimens (in which the whole zooid is withdrawn from the thoracic space), although it may be present and obscured by the crowded globular spicules. Cystodytes ramosus Kott, 1992 Cystodytes ramosus Kott, 1992b: 629. Distribution. New records: Queensland (Heron I, QM G307481; Swain Reefs, QM GH5731 G305480; Chauvel Reef, QM G315446; S. of Waining Reef, QM G304378). Formerly known only from the holotype, the new records demonstrate it to be a conspicuous and relatively common component of reef slope and inter-reefal habitats from 20 m and more (see Kott, 1992b). Description. Colonies are tight complex masses (to 8 cm diameter) of thick, cylindrical branches (to 3 cm diameter), rounded terminally. Newly recorded colonies are larger but otherwise similar to the holotype (Kott, 1992b)., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on pages 1619-1621, DOI: 10.1080/00222930110104258

Aplidium multiplicatum Sluiter, 1909 Aplidium multiplicatum Sluiter, 1909: 101; Kott, 1992a: 567 and synonymy. Aplidium controversum Monniot and Monniot, 1996: 135; 2001: 207. Distribution. New records: Queensland (Swain Reefs, QM G308426, G308422, G308425). This commonly encountered species has a wide range in the western Pacific from Hong Kong, the Philippines, Kiribati, Majura Atoll, Truk, Ponape and the Palau Is to Darwin and around the Australian coast. Although Kott (1992a: 567) states that it does not occur across the southern coast of the continent the species has been reported in St Vincent Gulf and off the Yorke Peninsula in South Australia. Description. The colonies have the characteristic colourless translucent test with soft vermilion zooids with a yellow thorax along each side of branching common cloacal canals with common cloacal apertures at junctions of the canals and opaque white granular material in the soft test that surrounds each zooid. Some Prochloron is on the surface. Larvae, in the newly recorded colonies, have a circle of lateral vesicles around the anterior half of the trunk. The three antero-median adhesive organs are very shallow (see Kott, 1992a). Remarks. Monniot, F. (1987), following Tokioka (1953, 1967) and Kott (1963) thought specimens from New Caledonia were synonymous with the eastern Pacific A. californicum (Ritter and Forsyth, 1917). Kott (1992a) assigned western Pacific and Australian specimens to A. multiplicatum Sluiter, 1900a, and included A. californicum: Monniot, F., 1987 from French Polynesia (but not the eastern Pacific species) as a synonym. Monniot and Monniot (1996) rejected that synonymy because the specimens require re-examination and erected a new species, A. controversum Monniot and Monniot, 1996, a wide-ranging western Pacific species (from New Caledonia, Palau Is and Australia) distinguished from A. multiplicatum by the presence of two rows of testis follicles in the posterior abdomen. However, testis follicles of the more than 60 specimens that Kott (1992a) examined, often are bunched, but are spread out in two rows in relaxed zooids and the degree of contraction affects the extent to which they are bunched (see Millar, 1975; Kott, 1992a). Valid grounds to separate these species are not available. Characteristic of the species, to which all authors refer, is the soft, translucent test and the rows of zooids. Of the synonyms of A. multiplicatum set out in Kott (1992a), the material described by Tokioka (1967), Van Name (1918), Nishikawa (1984) and A. californicum: Monniot, F., 1987 is consistent both in geographic range and morphology with the present species (see Kott, 1992a). In the detailed discussion of the synonymy of A. multiplicatum, Kott (1992a) specifies its difference from A. californicum, a distinct eastern Pacific species. The redescription of specimens of A. californicum from British Columbia (Monniot and Monniot, 1996) establishes that these specimens are an Aplidium species, but does not establish a distinction between A. californicum and A. multiplicatum (except for fewer stomach folds). This redescription is irrelevant to the establishment of A. controversum as a species distinct from A. multiplicatum., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on pages 1629-1630, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Sigillina pulvinus sp. nov. (figure 1C, plate 1A) Distribution. Type locality: Tasmania (Tasman Peninsula, Waterfall Bay outside Cathedral Cave in ledge in rock wall 10–13 m, coll. K. Gowlett Holmes, 21 October 94, syntypes SAM E2845). There are no further records. Description. Colonies are circular cushions with rounded margins, to 2 cm diameter. In life they are pinkish white with red zooids, their apertures showing at the surface and the zooids showing through the otherwise white, translucent test. Zooids, evenly spaced about 3 mm apart, are robust, 4–5 mm long (even when contracted). The abdomen and posterior abdominal stolon are about equal in length and the contracted thorax is shorter. Both apertures, on short cylindrical siphons each with six pronounced lobes around the opening, are anterior, on the upper surface of the colony. About 15 parallel muscle bands on each side of the thorax continue in a wide ventral band on the abdomen and the posterior abdominal stolon, surrounding the latter in longitudinal muscles. At each side of the distal extremity of the stout posterior abdominal extension, the muscles from each side are inserted into a small projecting horn from which the tips of the muscles project as sharp points. Three rows, each of about 16 long rectangular stigmata, are in the branchial sac. The descending limb of the gut loop consists of the oesophagus, an almost spherical, smooth stomach about half-way down the abdomen and a cylindrical duodenum and posterior stomach separated from each other and from the rectum by a short length of mid-intestine. The rectum is a long cylindrical tube occupying the whole ascending limb of the gut loop. Two large epicardial tubes, one each side of the ventral mid-line, extend through the abdomen and the one on the left projects down into the posterior abdominal vascular stolon. A single, large, yolky, spherical embryo, nearly 1.5 mm in diameter, with an ocellus, a small otolith and the tail wound all the way around the trunk, is in a brood pouch separated from the posterior end of the dorsal border of the thorax by a narrow constriction. These embryos are not sufficiently advanced to determine the form of other larval organs. Although embryos are in the brood pouch, gonads were not detected in these specimens. Remarks. The zooid is characteristic of this genus with a pronounced posterior abdominal stolon, three rows of stigmata, a brood pouch, a relatively short abdomen with a smooth spherical stomach half-way down it and parallel longitudinal thoracic muscles without conspicuous transverse ones. Despite the absence of gonads in the gut loop, the heart at the end of the abdomen and the smooth spherical stomach distinguish these specimens from Pseudodistoma (see Kott, 1992a). The circular colonies are more regular than the irregular ones of the South Australian S. fantasiana, which also is distinguished by the presence of more than one embryo developing in the less constricted brood pouch and without longitudinal muscles on the posterior abdominal stolon. The species most closely resembles the tropical S. signifera, but it has more regular colonies and smaller zooids. Like S. signifera, the species appears to be a member of the cyanea group of species (see Kott, 1992a) with a large posterior abdominal stolon with conspicuous muscles on it. Other Sigillina spp. have similar zooids, but different colonies., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1618, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Aplidium macrolobatum Kott, 1992 (plate 1D) Aplidium macrolobatum Kott, 1992a: 561. Distribution. New records: Queensland (Swain Reefs, QM G305732, G308413, G308424). The species is known from the Capricorn Group to Lizard I. in the Great Barrier Reef and on the mainland at Sarina. Description. The newly recorded colonies have vermilion or apricot-coloured zooids showing through the cream-coloured soft test that has sparse sand scattered throughout. The surface of one of the colonies (QM G305732) is raised into conical prominences. Zooids are arranged in double rows up the sides of these prominences, converging to the large terminal common cloacal apertures. They resemble colonies of some Holozoidae (namely Sycozoa or Distaplia). In preservative the zooids are orange, the pigment being present in the parietal thoracic wall. Zooids are as previously described, with a long trifid atrial lip from the upper rim of the opening, eight to nine rows of stigmata (about 10 per row), five deep longitudinal stomach folds, strong muscle bands on the thorax joining into a ventral band on the abdomen and posterior abdomen which, when contracted, bunches the gonads up behind the thorax. One of the newly recorded colonies (QM G308424) was on the back of a crab (see also Kott, 1992a: QM GH5663). The photographed colony (QM G305732) is 6 cm long., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1629, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Aplidium lunacratum Kott, 1992 Aplidium lunacratum Kott, 1992a: 558 and synonymy. Distribution. New record: New South Wales (Bass Point, QM G308509) Discontinuous records for the species are from Cervantes (WA) and from the Great Australian Bight to the Manning River (NSW) but are patchy., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1629, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Aplidium tabascum Kott, 1992 Aplidium tabascum Kott, 1992a: 589; Monniot and Monniot, 1996: 589. Distribution. New records: Queensland (Swain Reefs, QM G305367, G305408). Originally the species was known from a restricted range in the Capricorn Group and Swain Reefs but probably has a wider range in the western Pacific, being recorded from Madang, Papua New Guinea (Monniot and Monniot, 1996)., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1630, DOI: 10.1080/00222930110104258

Pycnoclavella tabella Kott, 1990 (Figure 8B) Pycnoclavella tabella Kott 1990a, p 77. Distribution Previously recorded (see Kott 1990a): South Australia (Spencer Gulf); Victoria (Portsea). New records: South Australia (Kangaroo I., 10–12 m, SAM E3292); Tasmania (Tasman Peninsula, 15–17 m, SAM E3291); Victoria (Portsea, SAM E3290). The species is usually in large aggregates on rocky walls and roofs of caves and overhanging ledges. This species has been recorded by scuba divers from relatively shallow waters. Description Specimens have the characteristic tangle of sandy, fragile, thin basal stolons, and narrow, often branching vertical stalks containing the long abdomina, also encased in thin, sandy test. On top of these vertical branches are the small spherical thoraces in thin, transparent, sand-free test, sometimes with a greenish oily appearance in life., Published as part of Kott, Patricia, 2006, Observations on non-didemnid ascidians from Australian waters (1), pp. 169-234 in Journal of Natural History 40 (3 - 4) on page 183, DOI: 10.1080/00222930600621601, http://zenodo.org/record/5232431, {"references":["Kott P. 1990 a. The Australian Ascidiacea Pt 2, Aplousobranchia (1). Memoirs of the Queensland Museum 29: 1 - 266."]}

Aplidium longithorax Monniot, 1987 Aplidium longithorax Monniot, F., 1987: 525; Monniot and Monniot, 1996: 139. Aplidium protectans: Kott, 1992a: 579. Not Amaroucium protectans Herdman, 1899: 73 < Polycitor protectans. Distribution. New records: Queensland (Swain Reefs, QM G305411, G305678). P 1. (A) Sigillina pulvinus sp. nov. (SAM E2845); (B) Eucoelium orientalis (SAM E2641); (C) Aplidium lenticulum (QM G305407); (D) Aplidium macrolobatum (QM G305732); (E) Botrylloides saccus sp. nov. (SAM E2868). (F) Botrylloides violaceus (QM G308550). Acknowledgements: (A, B, E) K. Gowlett Holmes; (C, D) S. List; (F) N. Coleman. The species is known from the Capricorn Group, the central and far northern Great Barrier Reef including Lizard I. and the Palau Is. Remarks. Both Herdman (1899) and Kott (1963, 1992a) misidentified a Polycitor species as an Aplidium (Amaroucium protectans Herdman, 1899). Fortunately, Monniot and Monniot (1996) examined the type specimen of Polycitor protectans (Herdman, 1899) and corrected this mistake. The species is large and conspicuous., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on pages 1627-1629, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Sigillina mjoebergi Harmeyer, 1919 Sigillina mjoebergi Hartmeyer, 1919: 117; Kott, 1990a: 96. Distribution. New records: Western Australia (Port Hedland, WAM 2.95; 791.88). This unusual species of problematical phylogeny is known only from the north-western Australian continental shelf., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1619, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Clavelina mirabilis Kott, 1972 Clavelina mirabilis Kott, 1972: 165; 1990a: 50. Distribution. New records: Tasmania (Bicheno, Hairy Wall dive site east of Governor’s I., rock slope, 15–20 m, SAM E2845). Previously known from only two specimens off Waldegrave I., S.A. The new record suggests that the species has a wide range in the Southern Ocean, extending into the Great Australian Bight and up the eastern coast of Tasmania. Description. The newly recorded specimen has a common cylindrical stalk but the thoracic parts of the zooids are independent of one another each in a separate covering of clear transparent test. Thoracic muscle bands are arranged as recorded for the type, namely 8E, 8B, 2D., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1616, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Eucoelium orientalis (Kott, 1990) Polycitorella orientalis Kott 1990a, p 187 and synonymy; not E. orientalis: Kott 2003. Distribution Previously recorded (see Kott 1990a): Western Australia (Rottnest I., Houtman’s Abrolhos); Queensland (Swain Reefs, Heron I., Coral Sea). New records: Tasmanian Canyons (Banks Strait, 168 m). Description Colonies are dome-shaped to stalked, with a single layer of moderately crowded spicules in the surface over an aspiculate layer of variable thickness. Spicules also are present internally in varying concentrations. Spicules are to 0.05 mm diameter with 5–13 stout conical rays in optical section. Large zooids open around the upper domed surface and converge toward the centre of the base of the colony. They are in a vegetative state, the abdomina breaking up into replicates. Remarks Eucoelium is known, from only eight species, from Japan, the Gulf of Suez and the western Indian Ocean, New Zealand, and tropical and temperate waters around the Australian continent (where three species are known). The present species has been recorded from the Great Barrier Reef and the Coral Sea, but the present record implies a wider range into temperate waters. All the known species of Eucoelium are very variable, but can be distinguished by their spicules, those of the present species being to 0.05 mm diameter with 5–15 rays. Eucoelium mariae (Michaelsen, 1924) from New Zealand has smaller spicules than the present species and the principally temperate E. coronaria Monniot, 1988 has larger spicules and its zooids are arranged in conspicuous circular systems. Eucoelium orientalis: Kott 2003 has large (to 0.09 mm diameter) globular spicules as well as smaller stellate ones and appears not to be a synonym of the present species. This genus and another polycitorid genus, Cystodytes, are the only aplousobranch genera outside the Didemnidae with the capacity to create calcareous spicules in the test. Although the spicules are very similar to those of the Didemnidae, a phylogenetic relationship is not implied. Like other species taken from the Tasmanian Canyons, the new record of the present species from so much further south than it was previously known provides further evidence that the Australian continent may constitutes a route for gene flow of shallow-water tropical species into temperate waters., Published as part of Kott, Patricia, 2006, Observations on non-didemnid ascidians from Australian waters (1), pp. 169-234 in Journal of Natural History 40 (3 - 4) on pages 189-190, DOI: 10.1080/00222930600621601, http://zenodo.org/record/5232431, {"references":["Kott P. 1990 a. The Australian Ascidiacea Pt 2, Aplousobranchia (1). Memoirs of the Queensland Museum 29: 1 - 266.","Kott P. 2003. New syntheses and new species in the Australian Ascidiacea. Journal of Natural History 37: 1611 - 1653.","Michaelsen W. 1924. Ascidiae Krikobranchiae von Neuseeland, den Chatham und den Auckland Inseln. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening i Kobenhavn 77: 263 - 434.","Monniot F. 1988. Ascidies de Nouvelle Caledonie V. Polycitoridae du lagon. Bulletin du Museum National d'Histoire Naturelle, Paris, Serie 4 10 A: 197 - 235."]}

Pycnoclavella detorta (Sluiter, 1904) Podoclavella detorta Sluiter, 1904: 6; not Kott, 1957b: 130. Clavelina detorta: Van Name, 1918: 133; Millar, 1975: 209; Monniot, F., 1988: 202; Monniot and Monniot, 2001: 231. Pycnoclavella detorta: Kott, 1990a: 71. Distribution. New records: Queensland (Swain Reefs, QM G305809). The new record confirms that the species is a common component of the West Pacific ascidian fauna (see Kott, 1990a). Larvae are present in the newly recorded specimens (collected in July). Remarks. Podoclavella detorta: Kott, 1957b (BM 1956. 5.2.19) has been re-examined. The specimens are long, narrow, horny stems up to 5 cm long, containing the long oesophageal neck and the slightly expanded distal part of the abdomen. They are joined to one another at their base by short stolons. However, the thoraces have disintegrated, and it was not possible to confirm Kott’s (1957b) description. Apart from the reported four rows of stigmata and longer and horny stalks, these specimens are like P. detorta. At this stage the significance of the reported differences is not known. Clavelina auracea Monniot, 1997a is also similar to P. detorta, except for ferilization of the eggs in a brood pouch at the postero-dorsal corner of the abdomen, five (rather than six) rows of stigmata, and the larvae. Although they lack the usual frontal plate of Clavelina larvae, the larval adhesive organs are not inverted tubes as in Pycnoclavellidae. Monniot (1997a) has not described the cerebral vesicle and it is not clear if an otolith is present or not. The affinities of this species are problematical, although the fertilization of eggs at the posterior end of the thorax suggests that it is closer to Clavelina than to Pycnoclavella., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1617, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089

Polycitor columna Kott, 1954 Polycitor columna Kott, 1954: 153. Distribution. Type locality: Tasmania (Maria I., 174– 155 m, syntypes AM Y1297). Description. Syntype colonies have been re-examined. They have thick fleshy stalks about the same length as, and only slightly less diameter than, the head. The stalks taper toward the base. The test is translucent without contained sand. Zooids open around the head by separate six-lobed apertures. About 15 longitudual thoracic muscles per side extend in a wide band along each side of the abdomen. The branchial sac has 16 rows of about 35 stigmata per row. The stomach has four shallow longitudinal furrows. The large larvae (trunk 1.6 mm long) are as previously described with the tail wound half-way around the trunk. Remarks. Kott’s (1954) report of only 12 stigmata in each row is wrong. On re-examination of these specimens at least 35 stigmata have been detected on each side. The species most resembles Polycitor calamus Kott, 1990a in its stalked colony, but P. calamus has a longer stalk, a shorter head, fewer stigmata per row, and 12 distinct longitudinal gastric folds., Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on pages 1623-1624, DOI: 10.1080/00222930110104258

Didemnum biglutinum Monniot F. 1995 (Figure 2C–D, 5, 6) Didemnum biglutinum Monniot F., 1995:300 Fig.1, pls 1A, III D. Monniot F. & Monniot C.: 1996 152 Fig. 9 C, pl. 2D; 2001:266. Material. coll. Coral Reef Research Foundation. Palau, Koror, Ngermeaus channel, 07°11.65’N – 134°22.65’E, 18m, 28/VII/2007, 0CDN 9581-X (MNHN A2 DID. C 601). Papua New Guinea, New Hanover, Nusandaul Isl., 02°37.30’S – 150°28.78’E, 11m, 03/VII/2003, 0CDN 9049-U (MNHN A2 DID. C 529). Maldives, N. Male Atoll, 04°11.43’N – 73°25.05’E, 23m, 22/IX/997, 0CDN 5316 (MNHN A2 DID. C 458). The colonies are flexible sheets of varied colours: white, yellow, brown or purple, with often two different colours in a same colony (Fig. 2C–D). The colony surface is smooth due to a thin layer of tunic without spicules. The common cloacal apertures are numerous raised in short chimneys. The spicules 20 to 30µm in diameter are balls composed of numerous rods (Fig. 5) and are dense in the whole colony thickness; clumps of pigment cells are located in the basal layer. The common cloacal cavity extends at the thoracic level. In formalin the zooids and larvae are brown. The oral siphon is short. The atrial aperture uncovers a large part of the branchial sac and is devoid of a languet. The lateral thoracic organs are ear-shaped, vertical above the fourth stigmata row (Fig. 6B). The muscular appendage is attached for the most of the length of the oesophagus. Abdomen and thorax are about the same length: 0.5mm. A single testis lobe protrudes from the base of the gut loop with 8 to 9 turns of the sperm duct The larval trunk 0.5mm in length has 2 divergent adhesive papillae edged with 4 long vesicles on each side (Fig. 6A).. They are not gemmiparous. Remarks. Didemnum biglutinum is widely distributed in the Pacific and Indian oceans. Specimens from all stations have the same colony structure, same zooids and larvae. Kott (2001) synonymized D. biglutinum with D. albopunctatum (Sluiter, 1909).The specimens that she describes, however, differ in having an atrial languet and a common cloacal cavity which penetrates below the zooid abdomens. The larvae are said to have 4 pairs of lateral ampullae, but have more in her figure (Fig.69C). Sluiter’s description is very short, gonads and larvae are not mentioned. I have examined Sluiter’s material which corresponds to several species. Kott (1981) established a lectotype for a sample labelled ZMA TU 4433 in the Amsterdam Museum, but her statement is based only on the spicule shape, this colony having no gonads and no larvae.Thus even the genus identification must remain doubtful. Kott (2004:52; 2004:2488; 2005:61; 2007:1176) has identified several didemnids as D. albopunctatum, but did not describe gonads and larvae. Consequently I do not retain the synonymy proposed by Kott, based solely on the spicule shape., Published as part of Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, pp. 1-29 in Zootaxa 2561 (1) on pages 5-6, DOI: 10.11646/zootaxa.2561.1.1, http://zenodo.org/record/5304193, {"references":["Kott, P. (2001) The Australian ascidiacea. Part 4, Aplousobranchia (3), Didemnidae. Memoirs of the Queensland Museum 47 (1), 1 - 407.","Sluiter, C. P. (1909) Die Tunicaten der Siboga-Expedition. II. Die merosomen Ascidien.","Kott, P. (1981) The ascidians of the reef flats of Fiji. Proceedings of the Linnean Society of New South wales, 105 (3), 147 - 212."]}

Trididemnum lanugineum n. sp. (Figures 2B, 3, 4) Material. Palau, coll. Coral Reef Research Foundation, Koror, SW Ngeruktabel, 07°14.83’N – 134°21.12’E, 10m, cavern, 01/ VI /2008, 0CDN9584-A (MNHN A2 TRI 188). The white colonies (Fig.2A) are crusts several centimetres in extent with round edges and a raspy surface. In formalin the thickness is about 2mm, in 3 layers. The surface layer is hard, filled with large spicules 170µm in diameter with numerous sharp rays (Fig. 3), and contains the oral siphons. The thoraces are grouped in pillars of tunic linked to the medium spicule-free layer of tunic that has a cotton-wool texture. Abdomens and larvae are enclosed in this soft but very resistant layer. The basal part of the colony is densely filled with spiny spicules. At the contact with the substrate, the spicules are almost balls with very short rays. The oral siphon is trumpet-like with a plain rim, very often broken during the dissection. The cloacal aperture has a wide horseshoe shape. Its dorsal side is covered by a long languet applied on the dorsal lamina (Fig. 4B); the circular lateral thoracic organs protrude from its margin. The branchial sac has 3 rows of long stigmata: 7 were counted in the first two rows and 6 in the third row per side. A muscular appendage was not found. The abdomen (Fig.4A) is smaller than the thorax. The gut loop is included into an opaque tissue. The single testis vesicle is placed above the bend of the intestine circled with 4 (rarely 5) turns of the sperm duct. Several larvae were found into the cotton-like layer of the colony, they do not seem totally developed. The tail is wound in ¾ of a turn around a trunk 0.85 to 1mm long (Fig. 4C). The 3 adhesive papillae have parallel stems. On each side, at their base are 4 round vesicles, obviously incompletely formed lateral ampullae. The internal structure is obscured by large opaque cells filling the larval body wall (partly figured Fig. 4C). Ocellus and otolith lie in a clear dorsal vesicle. The anterior part of a damaged larva, found in shreds of tunic, has 3 adhesive papillae and 8 lateral vesicles on each side, suggesting that these vesicles may divide at maturity. The originality of this new species consists in the unique structure of the atrial opening, widely open with a large dorsal languet and very large spicules., Published as part of Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, pp. 1-29 in Zootaxa 2561 (1) on pages 4-5, DOI: 10.11646/zootaxa.2561.1.1, http://zenodo.org/record/5304193