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Hemiancistrus landoni Eigenmann 1916 Figure 4 Hemiancistrus landoni Eigenmann 1916:84. Type locality: Naranjito, Ecuador. Hemiancistrus hammarlundi Rendahl 1937:2, Fig. 1. Type locality: Río Clementina system, northwest of Babahoyo, Los Ríos, Ecuador. Material examined. All from Ecuador, El Oro Province, MEPN-5948, 1 ex., 171.5 mm SL, La Cuca, canal de riego, río Arenillas, Granja PREDESUR, approx. 03°30'00"S 80°04'20"W, R. Barriga et al., 13 April 1979. MEPN- 5954, 1 ex., 88.6 mm SL, Río Piedras, curso superior del río Arenillas, approx. 03°38'10"S 79°55'40"W, R. Barriga et al., 12 April 1979. MEPN-17505, 1ex. 68.7 mm SL, Río Zaracay, approx. 03°38'55"S 79°52'180" W, P. Tufiño & R. Barriga, 20 November 2010. Guayas Province, MEPN-9820, 1 ex., 59.9 mm SL, Río Minas, donde cruza la cooperativa 23 de Noviembre, 9 km S de Naranjal, approx., 02°41'26"S 79°38'16"W, R. Barriga, 22 September 1992. MEPN-15118, 1 ex., 134.9 mm SL, Río Minas, donde cruza la cooperativa 23 de Noviembre, 9 km S de Naranjal, approx., 02°41'26"S 79°38'16"W, R. Barriga, 22 September 1992. Los Ríos Province, MEPN-9926, 8 ex. (7 Alc. 1 Dry skeleton), 128.4–205.8 mm SL, Río Catarama, cerca de la poblacion Corona, approx. 01°37'23"S 79°28'20"W, R. Barriga, 15 February 1997. MEPN-10389, 1 ex., 214.6 mm SL, Río Quevedo, approx. 01°02'04"S 79°27'43"W, C. Estrella, May 1953. MEPN-17049, 1 ex., 60.6 mm SL, Río Jujan, cerca de la población de Jujan, approx. 01°53'04S 79°33'06"W, S. Abril, 23 June 1986. MEPN-17050, 1 ex., 84.8 mm SL, Quevedo, G. Onore, November 1983. MEPN-18151, 3 ex., 192.3–213.4 mm SL, Río Las Juntas, afluente del río Babahoyo, approx. 01°52'06"S 79°22'43"W, M. Olalla, 12 March 1964. Manabí Province, MEPN-9099, 1 ex., 135.6 mm SL, Río Portoviejo, Laguna de Poza Honda, parte inferior, approx., 01°04'55"S 80°09'16"W, R. Barriga, 0 5 February 1993. MEPN-17952, 6 ex., 56.3–183.9 mm SL, Río Portoviejo, 1 km aguas abajo de la primera compuerta, approx., 01°06'21"S 80°09'41"W, R. Barriga et al., 0 3 October 1992. Hemiancistrus landoni is recognized among all species of Hemiancistrus sensu lato, except for H. medians by its abdomen, which is completely covered by small bony plates, and has a peculiar color pattern, rounded dark spots (vs. abdomen naked with light spots or plain). According to the figures and redescription indicated by Fisch- Muller et al. (2012), H. landoni can be recognized from H. medians, by its dorsal fin when folded does not reach the origin of the adipose fin versus the dorsal fin folded reaches the origin of the adipose fin. Further recognized by its head shape, which is less deep, and by its supraoccipital without a keel. In H. medians, the head is massive, and the supraoccipital has a keel. The eye is smaller in H. landoni than in H. medians, 15%–16% HL versus 18%–27% HL, respectively. Finally, the number of cheek odontodes is smaller in H. landoni than in H. medians, 10–20 vs. 20–60. Some large specimens show highly developed, long and pointed odontodes, on distal and dorsal portion of pectoral spines. This condition, as in other cases, may occur in sexually active adult males. Hemiancistrus landoni is an endemic species of the Pacific slope of Ecuador, and is found exclusively in aquatic systems of the Guayas River Basin and other water courses related to this basin. Comparative osteology. On the three species identified, we examined the bones that are related to the mobility of the opercular bone. The bones are the sphenotic, the compound pterotic (from now the pterotic), the hyomandibular and the opercular. The observed changes in the state or condition of each bone are related to the development of the musculature involved in the movement of the opercular and concomitant of the developed odontodes associated. The observed changes on the sphenotic occur on the posterior surface. Two conditions are perceived; in the first condition, the posterior region has an excavation or canal, extending from the middle of the bone to the ventral region of the bone; the area from the middle of the bone towards the dorsal region is massive (Fig. 6 A). The second condition is an excavation or canal that runs along the entire posterior surface, from the dorsal to the ventral. This channel is open in the ventral region, but towards the dorsal border it may be totally or partially open (Fig. 6 B). In H. annectens the first condition is observed, while in H. landoni and in H. furtivus, the second condition is observed, the canal is almost occluded at the dorsal border. The pterotic bone has on its anterior surface something similar to that indicated for the sphenotic. In the first condition we can observe the presence of a canal that is occluded or closed towards the dorsal region of the bone (Fig. 7 A). In the second condition the canal runs all or nearly all of the entire anterior surface of the pterotic bone (Fig. 7 B). By articulating the sphenotic and pterotic bones, the canal partially becomes a tunnel. The tunnel may be closed or open dorsally. In H. annectens, the first condition is observed, the pterotic canal is occluded or the tunnel is closed. In H. landoni and in H. furtivus, the second condition is observed, here the channel and tunnel runs almost all the anterior surface of the pterotic and the posterior surface of the sphenotic. In this case the tunnel closes towards the dorsal region. On the ventral and anterior border of the pterotic there is a fossa and a process (anterior process of the pteroticsupracleitrum according to Armbruster 2004). Again, two conditions related to this region are observed. In the first condition, the fossa and the process are slightly developed (Fig. 7 A). In the second, there is an appreciable development of the fossa and the process (Fig. 7 B). In H. annectens, the first condition is observed, while in H. landoni and in H. furtivus, the second condition is observed. On the analyzed species, the opercular bone presents two different forms (Fig. 8). In the first condition, the general shape or contour of the bone is almost triangular, similar to that described by Schaefer (1987) for Hypostomus plecostomus and Cochlidon cochliodon and Armbruster (2004) for Hemiancistrus maracaiboensis and Hypostomus taphorni (condition 0). In the second condition, the opercular has the contour of the opercular in the form of a paddle with a posterior dorsal projection, similar to that described by Schaefer (1987) for Peckoltia niveata and by Armbruster (2004) for Peckoltia sp. (Condition 1, Type- Peckoltia). The first condition of the opercular is present in H. annectens (Fig. 8 A), while the second condition is observed in H. landoni and H. furtivus (Fig. 8 B). The changes in opercular shape can be related to the increase in its rotational capacity at the point of support (condyle of articulation with the hyomandibular) and its properties as a lever. The conditions or states observed could be used to include the species under study into the Hypostomini or Ancistrini sensu Armbruster (2004). The changes noted in the three bones are linked to increased development (increased diameter or muscle thickness) and increased surfaces of origin and insertion of the levator operculi and dilator operculi muscles, which was evidenced during the preparation of skeletons. Discussion. The status of the genus Hemiancistrus is still controversial. The loss of the holotype of H. medians, and the way Kner (1854) presented the original description, generated doubts and discrepancies about the correct identity of this species. Fisch-Muller et al. (2012) established the taxonomic status and the identity of the type species, in spite of the descriptions provided by Günther (1864) and Regan (1904). We do not have specimens of H. medians, however, as indicated by Fisch-Muller et al. (2012) and Armbruster et al. (2015), H. medians and H. landoni share some external morphological characteristics not observed in the other species included in Hemiancistrus sensu lato, such as the presence of keels in the lateral plates of the body and a similar coloration pattern. The way the abdomen is covered appears to have some difference between H. medians and H. landoni, but none of the other species included in the group has such an extended abdominal covering. According with Armbruster et al. (2015) only H. medians is included in the genus Hemiancistrus. Therefore, the generic status of H. landoni and the other species remains uncertain. Hemiancistrus furtivus is represented at the MEPN by seven specimens in five cataloged lots. Only four are in good conditions, and/or with an appreciable standard length. Comparisons with original descriptions of the geographically nearest species were made carefully, and the external characters observed on H. furtivus shows that it is a new species. The belly is totally naked, the dorsal and caudal fins have a distinctive color pattern, and the small movable cheek odontodes differ from that of other Pacific Coast species described or placed in Hemiancistrus. In spite of this, the body color pattern observed on our specimens is very close with that reported by Eigenmann (1916) in the original description of H. landoni. He pointed out that the body has four oblique transverse saddles, the first behind the eyes, the second at the end of the dorsal fin, the third at the level of adipose fin, and the fourth at the caudal-fin origin. On our specimens of H. landoni, the presence of saddles is variable in that some are very evident while in others they are very faint or no traces are observed (Fig. 2). Two more species, were originally described from the Pacific versant of Ecuador, H. hammarlundi Rendahl 1937, and H. fugleri Ovchynnyk 1971. We agree with they are synonymous with H. landoni and H. annectens, respectively. The original description of H. hammarlundi was made on a unique specimen of 70.4 mm SL (Armbruster per. comm.). This specimen has small patches of granular plates on belly, and 20 movable odontodes developed in the cheek area. This is clearly different to that observed in H. furtivus. On the other hand, Ovchynnyk (1971) in the original description of H. fugleri, points out that the folded dorsal fin reaches or is very close to adipose-fin origin, and that the belly has small patches of granular plates. The specimen used was 91 mm SL. Only the examined juveniles of H. annectens show that the folded dorsal fin reaches the adipose-fin origin, and they also have small patches of granular plates on belly. The first character is useful to distinguish juveniles from H. landoni and H. furtivus, but the character changes with size; in large specimens of the three species, the folded dorsal fin does not reach the adipose-fin origin. Also, the figures provided by Ovchynnyk (1971) show a color pattern of the body and fins similar to H. annectens, and different to that observed in H. furtivus. Additionally, there are no developed cheek odontodes in H. fugleri. These results support the synonymy proposed by Armbruster et al. (2015) between the species previously described from Ecuador, and confirms the presence of the new species. The completely naked abdomen, the dark rounded dots on it, and the small movable cheek odontodes distinguish H. furtivus from all other species included in Hemiancistrus sensu lato (Armbruster et al. 2015). Finally, Armbruster et al. (2015) established at least three groups within Hemiancistrus sensu lato. The groupings are based on morphological similarity of species. The species H. landoni and H. furtivus are similar in overall body shape and the color pattern, but the cover of the abdomen and the degree development of mobile cheek odontodes are different. Despite these facts both species are included in the H. landoni group. Hemiancistrus annectens, H. aspidolepis, H. maracaiboensis, H. holostictus and H. wilsoni, inhabit the trans- Andean region, Panamá, Maracaibo lake basin, the rivers Magdalena, Cauca, Atrato, San Juan (Colombia), and Santiago (Ecuador). When comparing the original descriptions of all species, and specimens of H. annectens, it is evident that the external morphology, the meristic and morphometric data, and the color pattern are similar. This fact was previously detected by Schultz (1944), and mentioned by Regan (1913) and Eigenmann (1918). Some morphometric differences can be related with the size, the fixation and preservations conditions of the type specimens. At this moment, we do not have specimens of the other species on hand, and we are unable to offer diagnostics characters to recognize each species. A study to establish the status of each species is necessary, using direct comparison of fresh and well preserved specimens from each basin. In the meantime, the use of the names proposed to each basin is suggested. Recently, Armbruster et al. (2015) reassign to the genus Hypostomus the five species, as a consequence of the results obtained on phylogenetic analyses. The external morphology of the five trans-Andean species of Hypostomus seems to indicate that they do not belong in the genus Hemiancistrus or even to the Ancistrini group, as pointed in morphological and molecular phylogenies (Armbruster 2004, 2008; Lujan et al 2015). The comparative analysis of the bones related to the movement of the opercular, support the placement of H. annectens in the Hypostomini and H. landoni and H. furtivus in the Ancistrini. In order to establish the proper generic allocation of H. annectens a project is being carried out which includes a comparative analysis of the indicated bones, between this species and species traditionally included in the genus Hypostomus. In an analogous way, it is hoped to be able to compare osteologically the species included in the genus Hemiancistrus sensu lato to indicate its appropriate taxonomic status., Published as part of Provenzano, Francisco & Barriga, Ramiro, 2017, The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador, pp. 221-235 in Zootaxa 4272 (2) on pages 229-234, DOI: 10.11646/zootaxa.4272.2.4, http://zenodo.org/record/583853, {"references":["Eigenmann, C. H. (1916) New and rare fishes from South American rivers. Annals of the Carnegie Museum, 10 (1 - 2), 77 - 86, pls. 13 - 16.","Rendahl, H. (1937) Einige Fische aus Ecuador und Bolivia. Arkiv for Zoologi, 29 (3), A (11), 1 - 11.","Armbruster, J. W. (2004) Phylogenetic relationships of the suckermouth armored catfishes (Loricariidae) with emphasis on the Hypostominae and Ancistrinae. Zoological Journal of the Linnaean Society, 141 (1), 1 - 80.","Schaefer, S. A. (1987) Osteology of Hypostomus plecostomus (Linnaeus), with a phylogenetic analysis of the loricariid subfamilies (Pisces: Siluroidei). Contributions in Science, Natural History Museum of Los Angeles County, 394, 1 - 31.","Kner, R. (1854) Die Hypostomiden. Zweite Hauptgruppe der Familie der Panzerfische. (Loricata vel Goniodontes). Denkschriften der Mathematisch- Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften in Wien, 7, 251 - 286, pls. 1 - 5.","Gunther, A. (1864) Catalogue of the Fishes in the British Museum. Fol. 5. Catalogue of the Physostomi, Containing the Families Siluridae, Characinidae, Haplochitonidae, Sternoptychidae, Scopelidae, Stomiatidae in the Collection of the British Museum. Trustees, London, xxii + 455 pp.","Regan, C. T. (1904) A monograph of the fishes of the family Loricariidae. Transactions of the Zoological Society of London, 17 (3), 191 - 350, pls. 9 - 21.","Ovchynnyk, M. M. (1971) Unrecorded and new species of fishes from fresh waters of Ecuador. Zoologischer Anzeiger, 187 (1 - 2), 82 - 122.","Schultz, L. P. (1944) The catfishes of Venezuela, with descriptions of thirty-eight new forms. Proceedings of the United States National Museum, 94 (3172), 173 - 338, pls. 1 - 14.","Regan, C. T. (1913) The fishes of the San Juan River, Colombia. Annals and Magazine of Natural History, Series 8, 12 (71), 462 - 473.","Eigenmann, C. H. (1918) Eighteen new species of fishes from northwestern South America. Proceedings of the American Philosophical Society, 56 (7), 673 - 689.","Lujan, N. K., Armbruster, J. W., Lovejoy, N. & Lopez-Fernandez, H. (2015) Multilocus molecular phylogeny of the suckermouth armored catfishes (Siluriformes: Loricariidae) with a focus on subfamily Hypostominae. Molecular Phylogenetics and Evolution, 62, 269 - 288."]}

Key to the species commonly referred to as Hemiancistrus in Ecuador 1a Cheek region with four to eight, small, scarcely developed odontodes, visible mostly on adult specimens. These odontodes are associated with a bony plate, with reduced mobility or immobile. Dorsal fin folded reaches the origin of adipose fin in juveniles, or very close in adults. Caudal fin furcate. Santiago River Basin, province of Esmeraldas, NW of Ecuador............................................................................................. Hypostomus annectens 1b Cheek region with 12 or more developed odontodes, very small in juveniles. These odontodes are associated with connective tissue, they are located behind a bony plate or bony granulations, and are always mobile. Dorsal fin folded does not reach adipose-fin origin. Caudal fin emarginate..................................................................... 2 2a Ventral surface of the head and abdomen covered with small plates or granulations in specimens with 80 mm SL or more. Cheek odontodes 15 or more, well developed, longest (most posterior) greater than eye diameter. Dorsal fin with rounded dark dots arranged in vertical lines just in the middle of interradial membrane. Guayas, Arenillas, Puyango and Zaracay Rivers systems, provinces of Manabí, Los Rios, Guayas and El Oro..................................... Hemiancistrus landoni 2b Ventral surface of the head and abdomen completely naked in specimens 85 mm SL. Cheek odontodes 12–15, very few developed, longest less than eye diameter. Dorsal fin with irregular dark dots arranged in vertical lines on the interradial membrane close to the rays. Esmeraldas river system, provinces of Pichincha and Esmeraldas................. Hemiancistrus furtivus

Hemiancistrus furtivus new species Tables 1 & 2, Figures 1 & 2 Holotype. MEPN 11569, 83.0 mm SL, Ecuador, Pichincha Province, Esmeraldas River Basin, Río Silanche, río Blanco tributary, close to San Francisco de Silanche town, approx. 00°08´45´´N 79°16´38´´W, R. Barriga S. and A. Villacis, 0 7 November 2005, RBS05-24. Paratypes. All from Ecuador, Esmeraldas River Basin: MEPN 18411, 1 ex., 99.8 mm SL, Same data as holotype. MEPN 4475, 1 ex., 79.2 mm SL, C&S, Esmeraldas Province, Estero Chipo a 11 km de Quinindé, vía Golondrinas-Buenos Aires, afluente del Río Blanco, approx. 00°16'28"N 79°24'11"W, R. Barriga, and C. Cerón, 13 March 1985, RBS 85-96. MEPN 4488, 1 ex., mm SL, Esmeraldas Province, Estero Mendoza, in front to Estero Cole a 1 km de la población del mismo nombre, approx. 00°27'00" N 79°24'09"W, R. Barriga, C. Cerón, and J. Caicedo, 10 March 1985, RBS 85-91. MEPN 11421, 1 ex., 54.4 mm SL, Esmeraldas Province, Río Quinindé. 00°18'49''N 79°29'01''W, R. Barriga S. and A. Villacis, 0 5 November 2005, RBS 05-29. MEPN 11497, 1 ex., 70.3 mm SL, Esmeraldas Province, Río Chamba, a 5 km de la vía Quinindé-Esmeraldas, approx. 00°15'04''N 79°21'07''W, R. Barriga S. and A. Villacis, 0 1 November 2005, RBS 05-25. MCZ 48772, 13 ex., (12 Alc. 1 C&S), 55–97 mm SL, Esmeraldas Province, Río Tabuche, (Riachuelo) 49 km SE Esmeraldas, approx. 00°43'07''N 79°32'57''W, T. Roberts, C. Gilbert, and M. Silva, 20 October 1971. AUM 4242 (out MCZ 48772), 1 ex., 75.7 mm SL, same data MCZ 48772. MEPN-19058 (out MCZ 48772), 2 ex., (1 Alc. 1 C&S), 88.3–100.5 mm SL, same data MCZ 48772. Diagnosis. Hemiancistrus furtivus is distinguished from its unique geographical congener H. landoni and from H. medians by the totally naked abdomen and the color pattern of the dorsal and caudal fins. The dorsal fin has vertical rows of nearly rounded spots, dark (black or brown), on the interradial membranes, very near or attached to the rays, in H. landon i the dorsal fin has vertical rows of dark dots in the middle of the interradial membrane (Fig. 2), while in H. medians the dorsal fin has vertical rows of dark dots on the interradial membrane near and, over the rays. In H. furtivus, the dots are smaller, near the diameter of eye or less, whereas the dots are greater than eye diameter in H. landoni and H. medians. On the caudal fin, H. furtivus has transverse rows of spots nearly rounded, dark (black) randomly dispersed on the interradial membrane and rays, mostly on the distal area, where they have the appearance of transverse dark bands. In H. landoni, the caudal fin color pattern is similar to the dorsal fin. In H. furtivus there are between 12–15 cheek odontodes, each odontode emerges from a fleshy sheath, only its tip protrudes and is visible, the length of the longest odontode is less than eye diameter. In H. landoni there are more than 15 cheek odontodes, with a similar condition as H. furtivus, but around half of each odontode is visible, the length of longest (most posterior) is greater than the eye diameter. The new species can be recognized from all other species of Hemiancistrus sensu lato (Armbruster et al. 2015) except H. medians and H. landoni by the presence of dark rounded dots on the belly vs. belly whitish or with pale color homogeneous, without dots or spots. Finally, the species grouped in the ‘H.’ chlorostistus group from Brazil have patches of small plates on the abdomen while H. furtivus has the abdomen completely naked. Description. Morphometric data given in Table 1. Body robust, progressively compressed posteriorly. Caudal peduncle compressed, deep and robust. Dorsal profile of body from tip of snout through eyes, straight, with a slope close to 45°, from eyes to dorsal-fin origin gently convex, then gradually descending straight to caudal-fin origin. Ventral profile of body flat and straight or slightly concave. Ventral surface of head and belly naked to anus. From the anus to anal-fin origin, a straight naked band is present bordered by end of lateral plates. Urogenital papilla absent, the cloaca is a small but evident fleshy tube. Head wide and little depressed. Snout not projected with naked, oval tip. Eyes in dorsolateral position, orbits raised. Interorbital space broad. Supraoccipital slightly convex, posterior border rounded. Cheek mobile odontodes 12–15, tiny and thin. Each odontode arises from fleshy cylindrical base, and only tip protrudes. Tips orange or amber. Mobile odontodes roughly arranged in rosette pattern. Opercular bone exposed, visible externally, its lateral margin with small odontodes. Mouth oval or rounded. Upper lip narrow, usually covering premaxilla and only external surface is visible, edge is almost horizontal with very minute undulations. Internal surface papillose. Lower lip broad, its border crenulated. Lower lip surface papillose. Papillae smaller near border of lip increasing in size near lower jaws. Papillae of anterior lip similar in size to those near lower jaws. Maxillary barbels short, united to lower lip, leaving only tip free. Premaxilla slightly longer than dentary. Premaxillae nearly straight forming ~180° angle. Dentaries separate, forming open “V” between them, with angle 95°–105° between rami. Teeth numerous and minute, 25–35 teeth in each hemimandible. Premaxillary and dentary teeth of same size. Teeth incisor type, asymmetrically bifid, medial cusp longer and wider than lateral cusp. Medial cusp rounded or straight truncated, lateral cusp pointed. Tooth apex curved toward interior of mouth. Tooth apex yellowish, stalk whitish. Premaxillary and dentary with posterior small papillae. Plates on sides of body with keels. Lateral line plates 27 or 28. Post-anal plates 15 or 16. Inter-dorsal plates seven or eight, just in front of adipose-fin soine one small plate with keel. Dorsal-fin origin anterior to vertical passing through pelvic-fin origin. Dorsal-fin with one spinelet, one spine, and seven branched rays; when depressed tip does not reach adipose-fin origin. Adipose-fin well developed and always present. Spine of adipose fin wide, and straight. Pectoral-fin with one spine, and six branched rays. When depressed, pectoral-fin spine reaches less than one third of pelvic-fin spine length. Spine of pectoral-fin with a fleshy tip, and slightly shorter than first branched ray. Pelvic-fin with one spine and five branched rays; its posterior margin surpassed anal-fin base when depressed. Anal-fin with one flexible spine and four branched rays. Caudal-fin rays i,14,i. Caudal-fin emarginate. Color. Specimens preserved in 70% ethanol show little variation in base color. General color of head and dorsolateral surfaces of body dark brown. Dark (black), rectangular, ovals or rounded spots, of different sizes, and randomly arranged on head and body. Spots became smaller, concentrated, and faint or diffuse on snout. Two or three transverse, dark (black), and irregular saddles, anteriorly oriented, first at end of dorsal-fin base, second at adipose fin origin, and last at caudal-fin origin; saddles more visible in dorsal view. Patch of dark spots at caudalfin origin. Base color of abdomen uniform, creamy or whitish, with irregular, dark (black) spots. Dorsal fin with longitudinal rows of nearly rounded spots, dark (black or brown), on interradial membrane, near or attached to the rays. Caudal fin with transverse rows of spots nearly rounded, dark (black) randomly dispersed on interradial membrane and rays, mostly at distal area, where they appear to combine in transverse dark bands. Rest of fins with brown base color with dark (black) spots on spines, branched rays and interradial membranes (Figs. 1–2). Smallest specimen (54.4 mm SL) with dorsal and caudal fins with longitudinal or transverse, respectively, dark bands. Geographical distribution. The specimens were caught in the Esmeraldas River Basin, Provinces of Esmeraldas and Pichincha (Fig. 5). Etymology. The name of the species is taken from the Latin word furtivus meaning: attempting to pass unnoticed or hidden, and alludes to the fact that the species was not detected before despite being in the Ecuadorian Pacific region, one of the best known ichthyologically. An adjective., Published as part of Provenzano, Francisco & Barriga, Ramiro, 2017, The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador, pp. 221-235 in Zootaxa 4272 (2) on pages 223-228, DOI: 10.11646/zootaxa.4272.2.4, http://zenodo.org/record/583853

Key to the species commonly referred to as Hemiancistrus in Ecuador 1a Cheek region with four to eight, small, scarcely developed odontodes, visible mostly on adult specimens. These odontodes are associated with a bony plate, with reduced mobility or immobile. Dorsal fin folded reaches the origin of adipose fin in juveniles, or very close in adults. Caudal fin furcate. Santiago River Basin, province of Esmeraldas, NW of Ecuador............................................................................................. Hypostomus annectens 1b Cheek region with 12 or more developed odontodes, very small in juveniles. These odontodes are associated with connective tissue, they are located behind a bony plate or bony granulations, and are always mobile. Dorsal fin folded does not reach adipose-fin origin. Caudal fin emarginate..................................................................... 2 2a Ventral surface of the head and abdomen covered with small plates or granulations in specimens with 80 mm SL or more. Cheek odontodes 15 or more, well developed, longest (most posterior) greater than eye diameter. Dorsal fin with rounded dark dots arranged in vertical lines just in the middle of interradial membrane. Guayas, Arenillas, Puyango and Zaracay Rivers systems, provinces of Manabí, Los Rios, Guayas and El Oro..................................... Hemiancistrus landoni 2b Ventral surface of the head and abdomen completely naked in specimens 85 mm SL. Cheek odontodes 12–15, very few developed, longest less than eye diameter. Dorsal fin with irregular dark dots arranged in vertical lines on the interradial membrane close to the rays. Esmeraldas river system, provinces of Pichincha and Esmeraldas................. Hemiancistrus furtivus, Published as part of Provenzano, Francisco & Barriga, Ramiro, 2017, The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador, pp. 221-235 in Zootaxa 4272 (2) on page 223, DOI: 10.11646/zootaxa.4272.2.4, http://zenodo.org/record/583853

Hemiancistrus platyrhynchus: ANSP-70512, Holotype, 70.7 mm SL, Colombia, Florencia, Orteguasa River basin, Brother Nic��foro Mar��a, 1931. ANSP-70513, Paratype, 67.75 mm SL, Colombia, Florencia, Orteguasa River basin, Brother Nic��foro Mar��a, 1931. MBUCV-V-18376 (ex. ANSP-84570), 3 ex., 37.4���56.1 mm SL, Colombia, Brother Nic��foro Mar��a, 1931., Published as part of Ardila, Carlos, 2017, A new species of the catfish genus Cordylancistrus (Siluriformes, Loricariidae) from the Sierra Nevada de Santa Marta, Colombia, pp. 256-266 in Zootaxa 4329 (3) on page 265, DOI: 10.11646/zootaxa.4329.3.4, http://zenodo.org/record/1002500

Hemiancistrus daguae : FMNH-56052, Holotype, 60.4 mm SL, Colombia, Caldas. FMNH-56053, 3 Paratypes, 32.3���75.8 mm SL, Colombia, Caldas. FMNH-56054, 2 Paratypes, 33.6���65.9 mm SL, Colombia, Caldas., Published as part of Ardila, Carlos, 2017, A new species of the catfish genus Cordylancistrus (Siluriformes, Loricariidae) from the Sierra Nevada de Santa Marta, Colombia, pp. 256-266 in Zootaxa 4329 (3) on page 265, DOI: 10.11646/zootaxa.4329.3.4, http://zenodo.org/record/1002500

Hemiancistrus cerrado is described from the tributaries of rio Araguaia, rio Tocantins basin. Hemiancistrus cerrado has external similarities with H. megalopteryx and H. punctulatus from coastal streams of southern Brazil, and can be distinguished by having a larger internarial width, 15.9-21.1% of head length (vs. 11.2-14.0% in H. megalopteryx and 11.2-13.9% in H. punctulatus) and, with little overlap, by the larger adipose-fin spine length, 9.4-13.6% of standard length (vs. 7.1-8.7% in H. megalopteryx and 7.4-10.0% in H. punctulatus). Hemiancistrus cerrado further differs from H. megalopteryx by having the pectoral-fin spine reaching maximally to the middle of the pelvic-fin spine when adpressed in adult males (vs. reaching tip). Hemiancistrus cerrado differs from other members of Hemiancistrus by color and numerous morphometric and meristic data. Hemiancistrus cerrado é descrito de tributários da margem esquerda do rio Araguaia, bacia do rio Tocantins. Hemiancistrus cerrado possui similaridades externas com H. megalopteryx e H. punctulatus de drenagens costeiras do sul do Brasil, e pode ser separado das duas espécies pela maior distância entre as narinas, 15.9-21.1% do comprimento da cabeça (vs. 11.2-14.0% em H. megalopteryx e 11.2-13.9% em H. punctulatus), e, com alguma sobreposição, pela maior nadadeira adiposa, 9.4-13.6% do comprimento padrão (vs. 7.1-8.7% em H. megalopteryx e 7.4-10.0% em H. punctulatus); de H. megalopteryx ainda difere por espinho da nadadeira peitoral de machos adultos se estendendo até o meio do espinho da nadadeira pélvica quando adpressa (vs. se estendendo até a ponta do espinho). Hemiancistrus cerrado difere de outros congêneres pela coloração e diversos dados merísticos e morfométricos.

Two new species of Hemiancistrus are described: Hemiancistrus votouro n. sp. and Hemiancistrus meizospilos n. sp. from upper rio Uruguai basin. They differ from their congeners except H. chlorostictus, H. megacephalus, and H. macrops by the presence of light dots on fins and lateral and dorsal portions of head and body. Hemiancistrus votouro and H. meizospilos differ from the species above by meristic and morphometric data and by the color pattern. Duas novas espécies de Hemiancistrus são descritas: Hemiancistrus votouro e Hemiancistrus meizospilos da bacia do rio Uruguai superior. Elas diferem dos seus congêneres, exceto de H. chlorostictus, H. megacephalus e H. macrops, pela presença de pontos claros distribuídos nas nadadeiras e nas porções laterais e dorsal da cabeça e do corpo. Hemiancistrus votouro e H. meizospilos diferem das espécies citadas acima por dados merísticos e morfométricos e pelo padrão de colorido.

Three new species of saddled hypostomine loricariids are described. According to a recent phylogenetic analysis, these species are members of the genus Peckoltia. The species differ from all described Peckoltia except Peckoltia furcata and Peckoltia sabaji by having the dentaries meet at an angle greater than 90°. The species also have similarities to Hemiancistrus, and can be separated from all described species by having dorsal saddles. We discuss the taxonomy of Peckoltia, Hemiancistrus, and allied genera and recognize Ancistomus as valid for Peckoltia feldbergae, Hemiancistrus micrommatos, Ancistrus snethlageae, Hemiancistrus spilomma, and Hemiancistrus spinosissimus. We recommend descriptions of genera for several clades of Hemiancistrus and restriction of Hemiancistrus to the type species of the genus, Hemiancistrus medians. Chaetostomus macrops is transferred to Pseudancistrus and recognized as a junior synonym of Pseudancistrus megacephalus. The Hemiancistrus annectens group of species (Hemiancistrus annectens, Hemiancistrus argus, Hypostomus aspidolepis, Hemiancistrus fugleri, Hemiancistrus holostictus, Hemiancistrus maracaiboensis, Hemiancistrus panamensis, Hemiancistrus wilsoni) are recognized in Hypostomus. Multivariate analysis reveals that the newly described species differ from one another in shape space, but overlap broadly with other Peckoltia (Peckoltia lujani), narrowly with other Peckoltia (Peckoltia greedoi), or broadly with Etsaputu (Peckoltia ephippiata).

Peckoltia contains 12 described species, eight of which are considered valid. Peckoltia arenaria, P. filicaudata, and P. ucayalensis are recognized as synonyms of P. bachi and P. kuhlmanni is recognized as a synonym of P. vittata. In addition, two new species are described. The type species of Peckoltichthys and Sophiancistrus are synonyms of P. bachi and both genera are recognized as junior synonyms of Peckoltia. The species of Peckoltia range throughout much of the Amazon basin, the upper Orinoco, the upper Essequibo, and perhaps the Maroni, and can be identified from most other ancistrins by having dentaries that form angle of 90° or less and from others with angled dentaries by lacking the synapomorphies of those genera. The species of Peckoltia vary from one another mostly in coloration. Peckoltia braueri, P. caenosa n. sp., P. cavatica and P. vittata lack spots on the head while the other species have them. Peckoltia braueri and P. cavatica have orange bands in the dorsal and caudal fins and have the bones and plates of the head and nape outlined in black (vs. no orange bands and head plates and bones not outlined in black in P. caenosa and P. vittata). Peckoltia caenosa has a color pattern consisting of dark vermiculations on the head and abdomen (vs. saddles or blotches on the head and faint dark spots on the abdomen in P. vittata). Among the species with spots on the head, P. lineola n. sp. and P. vermiculata have some of the spots combining to form vermiculations (vs. spots free in P. bachi, P. brevis, P. furcata, and P. oligospila) with the vermiculations larger than the pupil in P. lineola and narrower in P. vermiculata and the vermiculations radiating from a central point in P. vermiculata vs. no such pattern in P. lineola. Peckoltia bachi can be identified from the other species by having widened pelvic-fin spines that can be pulled ventrally such that they are completely ventral and parallel to the body (vs. pelvic-fin spines narrow and cannot be adducted ventral to body) and by having the eye low on the head (vs. high). Peckoltia brevis can be identified from P. furcata and P. oligospila by having well-developed dorsal saddles (vs. saddles faint), no spots on the body behind the nape (vs. spots generally present behind the nape); from P. oligospila by having bands in the caudal fin (vs. spots); and from P. furcata by having the lower caudal-fin spine longer than the upper (vs. upper spine longer). Peckoltia furcata can be identified from P. oligospila by having the upper caudal-fin spine longer than the lower (vs. lower spine longer) and by having bands in the caudal fin (vs. spots). Ancistrus yaravi had been recognized as a species of Peckoltia. The type of A. yaravi is lost, but the original description suggests that the species is the senior synonym of Neblinichthys roraima. A revised morphological phylogeny demonstrates the lack of support for Peckoltia and Hemiancistrus as monophyletic, and phenetic definitions are provided for the two genera. The phylogeny also demonstrates a lack of support of the genus Watawata.

H. megacephalus: MBUCV V 16972, 3 ex., 84.9-107.4 mm SL., Published as part of Francisco Provenzano & Nadia Milani, 2006, Cordylancistrus nephelion (Siluriformes, Loricariidae), a new and endangered species of suckermouth armored catfish from the Tuy River, north-central Venezuela., pp. 29-41 in Zootaxa 1116 on page 39

Hemiancistrus maracaiboensis: MBUCV V 16353, 1 ex., 206.8 mm LS., Published as part of Francisco Provenzano & Nadia Milani, 2006, Cordylancistrus nephelion (Siluriformes, Loricariidae), a new and endangered species of suckermouth armored catfish from the Tuy River, north-central Venezuela., pp. 29-41 in Zootaxa 1116 on page 39

A phylogenetic analysis of nearly all genera of the Hypostominae and the Ancistrinae is provided based on osteology, external anatomy, and digestive tract anatomy. The results suggest that the Hypostominae is a paraphyletic assemblage. Delturus and Upsilodus form a monophyletic group sister to all other loricariids. Hemipsilichthys, Isbrueckerichthys, Kronichthys, and Pareiorhina form a monophyletic group with Neoplecostomus and the Hypoptopomatinae and are transferred to the Neoplecostominae. The remainder of the Hypostominae is made paraphyletic by the continuing recognition of the Ancistrinae. Ancistrinae is returned to the Hypostominae and recognized as a tribe, Ancistrini. In addition, four new tribes (Corymbophanini, Hypostomini, Pterygoplichthini, and Rhinelepini) are described. Hypostomus is also paraphyletic, the bulk of it forming a monophyletic clade with Aphanotorulus, Cochliodon, and Isorineloricaria. All of the potential monophyletic groups within Hypostomus grade into one another; therefore, Aphanotorulus, Cochliodon, and Isorineloricaria are placed in the synonymy of Hypostomus. Pterygoplichthys and Glyptoperichthys are also polyphyletic, and Liposarcus and Glyptoperichthys are recognized as synonyms of Pterygoplichthys. Sister to Pterygoplichthys is the Hemiancistrus annectens group (including Hypostomus panamensis) which represents an undescribed genus. The phylogeny presented is compared with previous hypotheses. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141, 1−80.

Hemiancistrus votouro, new species Fig. 1 Holotype. MCP 33594,133.9 mm SL (female); Brazil: Rio Grande do Sul: Benjamin Constant: arroio Lageado Grande (tributary of the rio Passo Fundo, rio Uruguai basin), ca. 2.5 km NE from Votouro Indian Reserve (27°26’50"S 52°37’5"W), W. Bruschi Jr. & J. F. P. da Silva, 1 May 2002. Paratypes. MCP 29661, 99.5-141.2 mm SL (3 males and 2 females); MNRJ 25920, 99.5-136.3 mm SL (1 male and 1 female), collected with the holotype. Diagnosis. Hemiancistrus votouro differs from all other Hemiancistrus except H. chlorostictus, H. meizospilos, H. megacephalus, and H. macrops by the presence of light dots on all fins and the lateral and dorsal portions of body. Hemiancistrus votouro differs from H. chlorostictus by the number of premaxillary teeth (61-79 vs. 30-54), by the larger adipose-fin spine (9.0-10.4% SL vs. 5.8-8.0% SL; Fig. 2), by the deeper caudal peduncle (11.0-11.8% SL vs. 9.6-10.4% SL), by the larger pectoral fin (36.2-41.3% SL vs. 30.6-35.4 % SL), by the larger exposed portion of cleithrum (11.2-12.7% SL vs. 9.3-10.6% SL; Fig. 3), by the narrower body at dorsal-fin origin (17.9-19.8% SL vs. 19.9-25.3% SL) and first anal-fin pterygiophore not exposed (vs. exposed). Hemiancistrus votouro is distinguished from H. meizospilos by the smaller orbit diameter (14.5-16.7% HL vs.16.7-21.0% HL; Fig. 4) and by the much smaller light markings (one to three dots per plate vs. one large dot occupying one to three plates and skin between them). Hemiancistrus votouro differs from H. megacephalus and H. macrops by the number of the light markings per body plate (one to three small dots per plate vs. only one large dot on each body plate). Description. Meristic and proportional measurements in Table 1. Dorsal profile of body gently arched from snout tip to dorsalfin origin. Body narrowing progressively caudally from cleithrum. Trunk mostly straight and tapering slightly to caudal-fin base. Trunk and caudal peduncle mostly rounded in cross section, slightly flattened ventrally, more compressed caudally. Ventral surface flattened. Head slightly concave between orbits; dermal plates not carinate; upper margin of orbits (dorsolateral margin of frontal and sphenotic bones) slightly elevated. Snout broad and rounded anteriorly, slightly concave anterior to nares. Odontodes not forming keels on lateral plates. Dorsal, supramedial, median, and inframedial plate rows complete from head to caudal fin. Abdomen without platelets, except for small patch of platelets between pectoral fins. Cheek plates present on lateral margins of head; snout plates reduced to few granular platelets, absent in rectangular area on snout tip; five rows of plates on caudal peduncle; 25-26 plates in medial plate row. Nuptial males with hypertrophied odontodes slightly larger on tip of pectoralfin spine. Cheek plates evertible with 13-24 hypertrophied odontodes with curved tips, longest odontode one and half times eye diameter (juveniles with fewer and shorter odontodes than adults). Opercle supporting about 15-20 small odontodes in juveniles and adults. Preopercle covered by small platelets. Eyes small (14.5-16.7% HL), iris with large dorsal flap. Lips large, occupying most of ventral surface of head. Lower lip mostly covered with papillae, except for smooth band near its border. Maxillary barbel free and pointed, typically reaching about one third of way from its origin to gill opening. Some individuals with one or both barbels bifurcated. Teeth small, bifid; medial cusp large, blade-like, and slightly rounded; lateral cusp minute, pointed, never reaching more than one third of mesial cusp length. Premaxillary teeth 61 to 79 (mean=71.4). Dentary teeth 61 to 84 (mean=71.8). Upper and lower jaw rami form angles slightly less than 180 o. Dorsal-fin rays II,7; reaching adipose-fin origin when depressed. Dorsal fin originating at vertical line in front of pelvic-fin base; dorsal-fin spinelet V-shaped, locking mechanism functional. Pectoral-fin rays I,6; tip of spine reaching beyond half-length of pelvic-fin origin in both sexes, when depressed. Pelvic-fin rays I,5; tip of spine reaching slightly beyond anal-fin origin when depressed. Anal-fin rays I,4. First anal-fin pterygiophore not exposed. Caudal-fin rays I,14,I; caudal fin slightly truncate. Adipose-fin spine large and thick. Color in alcohol. Dorsal and lateral surface of body and head dark gray, covered with small light dots, less numerous on caudal peduncle; one to three dots per body plate. Ventral body surface whitish. Fins dark gray with light dots on rays, occasionally also on membranes (Fig.1). Some specimens with light dots almost imperceptible. Distribution. Known only from type-locality. The arroio Lageado Grande, tributary of the rio Erechim, rio Passo Fundo system (upper rio Uruguai basin), Rio Grande do Sul, Brazil (Fig. 5). Ecological notes. Type-locality for this species is a 2-5 m wide stream, with rocky and sandy bottom, small rapids separated by pools and marginal vegetation moderately preserved. Etymology. The specific name votouro (noun in apposition) is given in honor of the Votouro Indian Reserve, situated on Benjamin Constant, Rio Grande do Sul, Brazil.

Hemiancistrus votouro, new species Fig. 1 Holotype. MCP 33594,133.9 mm SL (female); Brazil: Rio Grande do Sul: Benjamin Constant: arroio Lageado Grande (tributary of the rio Passo Fundo, rio Uruguai basin), ca. 2.5 km NE from Votouro Indian Reserve (27°26’50"S 52°37’5"W), W. Bruschi Jr. & J. F. P. da Silva, 1 May 2002. Paratypes. MCP 29661, 99.5-141.2 mm SL (3 males and 2 females); MNRJ 25920, 99.5-136.3 mm SL (1 male and 1 female), collected with the holotype. Diagnosis. Hemiancistrus votouro differs from all other Hemiancistrus except H. chlorostictus, H. meizospilos, H. megacephalus, and H. macrops by the presence of light dots on all fins and the lateral and dorsal portions of body. Hemiancistrus votouro differs from H. chlorostictus by the number of premaxillary teeth (61-79 vs. 30-54), by the larger adipose-fin spine (9.0-10.4% SL vs. 5.8-8.0% SL; Fig. 2), by the deeper caudal peduncle (11.0-11.8% SL vs. 9.6-10.4% SL), by the larger pectoral fin (36.2-41.3% SL vs. 30.6-35.4 % SL), by the larger exposed portion of cleithrum (11.2-12.7% SL vs. 9.3-10.6% SL; Fig. 3), by the narrower body at dorsal-fin origin (17.9-19.8% SL vs. 19.9-25.3% SL) and first anal-fin pterygiophore not exposed (vs. exposed). Hemiancistrus votouro is distinguished from H. meizospilos by the smaller orbit diameter (14.5-16.7% HL vs.16.7-21.0% HL; Fig. 4) and by the much smaller light markings (one to three dots per plate vs. one large dot occupying one to three plates and skin between them). Hemiancistrus votouro differs from H. megacephalus and H. macrops by the number of the light markings per body plate (one to three small dots per plate vs. only one large dot on each body plate). Description. Meristic and proportional measurements in Table 1. Dorsal profile of body gently arched from snout tip to dorsalfin origin. Body narrowing progressively caudally from cleithrum. Trunk mostly straight and tapering slightly to caudal-fin base. Trunk and caudal peduncle mostly rounded in cross section, slightly flattened ventrally, more compressed caudally. Ventral surface flattened. Head slightly concave between orbits; dermal plates not carinate; upper margin of orbits (dorsolateral margin of frontal and sphenotic bones) slightly elevated. Snout broad and rounded anteriorly, slightly concave anterior to nares. Odontodes not forming keels on lateral plates. Dorsal, supramedial, median, and inframedial plate rows complete from head to caudal fin. Abdomen without platelets, except for small patch of platelets between pectoral fins. Cheek plates present on lateral margins of head; snout plates reduced to few granular platelets, absent in rectangular area on snout tip; five rows of plates on caudal peduncle; 25-26 plates in medial plate row. Nuptial males with hypertrophied odontodes slightly larger on tip of pectoralfin spine. Cheek plates evertible with 13-24 hypertrophied odontodes with curved tips, longest odontode one and half times eye diameter (juveniles with fewer and shorter odontodes than adults). Opercle supporting about 15-20 small odontodes in juveniles and adults. Preopercle covered by small platelets. Eyes small (14.5-16.7% HL), iris with large dorsal flap. Lips large, occupying most of ventral surface of head. Lower lip mostly covered with papillae, except for smooth band near its border. Maxillary barbel free and pointed, typically reaching about one third of way from its origin to gill opening. Some individuals with one or both barbels bifurcated. Teeth small, bifid; medial cusp large, blade-like, and slightly rounded; lateral cusp minute, pointed, never reaching more than one third of mesial cusp length. Premaxillary teeth 61 to 79 (mean=71.4). Dentary teeth 61 to 84 (mean=71.8). Upper and lower jaw rami form angles slightly less than 180 o. Dorsal-fin rays II,7; reaching adipose-fin origin when depressed. Dorsal fin originating at vertical line in front of pelvic-fin base; dorsal-fin spinelet V-shaped, locking mechanism functional. Pectoral-fin rays I,6; tip of spine reaching beyond half-length of pelvic-fin origin in both sexes, when depressed. Pelvic-fin rays I,5; tip of spine reaching slightly beyond anal-fin origin when depressed. Anal-fin rays I,4. First anal-fin pterygiophore not exposed. Caudal-fin rays I,14,I; caudal fin slightly truncate. Adipose-fin spine large and thick. Color in alcohol. Dorsal and lateral surface of body and head dark gray, covered with small light dots, less numerous on caudal peduncle; one to three dots per body plate. Ventral body surface whitish. Fins dark gray with light dots on rays, occasionally also on membranes (Fig.1). Some specimens with light dots almost imperceptible. Distribution. Known only from type-locality. The arroio Lageado Grande, tributary of the rio Erechim, rio Passo Fundo system (upper rio Uruguai basin), Rio Grande do Sul, Brazil (Fig. 5). Ecological notes. Type-locality for this species is a 2-5 m wide stream, with rocky and sandy bottom, small rapids separated by pools and marginal vegetation moderately preserved. Etymology. The specific name votouro (noun in apposition) is given in honor of the Votouro Indian Reserve, situated on Benjamin Constant, Rio Grande do Sul, Brazil., Published as part of Cardoso, Alexandre Rodrigues & Silva, José Francisco Pezzi da, 2004, Two new species of the genus Hemiancistrus Bleeker (Teleostei: Siluriformes: Loricariidae) from the upper rio Uruguai basin, pp. 1-8 in Neotropical Ichthyology 2 (1) on page 2, DOI: 10.1590/S1679-62252004000100001, http://zenodo.org/record/5416860