A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species

737 Neotropical Ichthyology, 8(4):737-770, 2010 Copyright © 2010 Sociedade Brasileira de Ictiologia A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species Vinicius A. Bertaco and Luiz R. Malabarba The species of Hemibrycon occurring in the east of the Andean Cordilleras are reviewed based on their type series and additional specimens. Nine species are redescribed: H. beni from río Beni basin, Bolivia; H. helleri from the upper rio Ucayali, Peru; H. huambonicus from the ríos Huallaga and Marañon basins, Peru; H. jeslkii from the upper portions of ríos Marañon, Ucayali and Madeira basins, Bolivia, Brazil, and Peru; H. metae from río Orinoco basin, Colombia and Venezuela, and Caribbean coastal basins of Venezuela; H. polyodon (type species) from río Pastaza basin, Ecuador; H. surinamensis from coastal basins of French Guiana and Suriname, and from lower rios Tapajós, Tocantins and Xingu basins, Brazil; H. taeniurus from river basins from Trinidad Island, Trinidad and Tobago, and H. tridens from upper río Ucayali basin, Peru. Two new species are described: H. inambari from the upper río Madre de Dios basin, Peru and H. mikrostiktos from río Ucayali basin, Peru. These species are distinguished among themselves mainly by the color pattern, and meristic characters. The distribution area of the genus is enlarged reaching the lower Tapajós, Tocantins and Xingu river basins, Brazil, with the first record of the occurrence of H. surinamensis in this country. A new description and diagnosis is provided for the type species of the genus, regardless its recent redescription. The type series of H. helleri that was previously considered dubious is found and described. Hemibrycon coxeyi and H. pautensis are considered junior synonyms of H. polyodon. Tetragonopterus (Hemibrycon) trinitatis, previously considered species inquirenda in Characidae, and Hemibrycon guppyi are junior synonyms of H. taeniurus. Hemibrycon orcesi is transferred to Boehlkea. A taxonomic key for the species of the genus to the east of the Andean Cordilleras is presented. As espécies de Hemibrycon que ocorrem a leste das Cordilheiras dos Andes são revisadas com base na análise do material tipo e exemplares adicionais. Nove espécies são redescritas: H. beni da bacia do río Beni, Bolívia; H. helleri do alto río Ucayali, Peru; H. huambonicus para as bacias dos ríos Huallaga e Marañon, Peru; H. jeslkii para as porções superiores das bacias dos rios Marañon, Ucayali e Madeira, Bolívia, Brasil e Peru; H. metae para a bacia do río Orinoco, Colômbia e Venezuela, e bacias costeiras do Caribe na Venezuela; H. polyodon (espécie-tipo) para a bacia do río Pastaza, Equador; H. surinamensis para as bacia costeiras da Guiana Francesa e Suriname, e porção inferior das bacias dos rios Tapajós, Tocantins e Xingu, Brasil; H. taeniurus para os rios da ilha de Trinidad, Trinidad and Tobago; H. tridens para a bacia do alto río Ucayali, Peru. Duas espécies novas são descritas: H. inambari para a bacia do alto río Madre de Dios, Peru e H. mikrostiktos para a bacia do río Ucayali, Peru. Estas espécies distinguem-se principalmente pelo padrão de colorido e caracteres merísticos. A área de distribuição do gênero é ampliada para as porções inferiores das bacias do Tapajós, Tocantins e Xingu, Brasil, com o primeiro registro de H. surinamensis para este país. Uma nova diagnose e descrição são fornecidas para a espécie-tipo do gênero, apesar de ter sido recentemente redescrita. A série-tipo de H. helleri previamente considerada questionável é encontrada e descrita. Hemibrycon coxeyi e H. pautensis são considerados sinônimos juniores de H. polyodon. Tetragonopterus (Hemibrycon) trinitatis, anteriormente considerada como species inquirenda em Characidae, e Hemibrycon guppyi são sinônimos juniores de H. taeniurus. Hemibrycon orcesi é transferida para Boehlkea. É apresentada uma chave taxonômica para as espécies do gênero a leste das Cordilheiras dos Andes. Key words: Neotropical, Taxonomy, Boehlkea, Bryconamericus, Freshwater fish. Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Zoologia, Laboratório de Ictiologia. Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil. [email protected], [email protected] A review of the Cis-Andean species of Hemibrycon 738 Introduction Hemibrycon Günther, 1864 is a Neotropical genus of characid fishes comprising twenty eight valid species, sixteen Trans-Andean species distributed in the coastal drainages of the Pacific slope of Panama and in between Caribean slopes of Panama and Venezuela (including the ríos Atrato and Magdalena and Lago Maracaibo basins), and twelve Cis-Andean species distributed in the range between Caribbean coastal basins of Venezuela to lower rio Tocantins basin (including the río Orinoco basin, Trinidad and Tobago island, and río Amazon basin in Bolivia, Brazil, Ecuador, and Peru; Bertaco et al., 2007; Eschmeyer, 2010; this paper). The genus Hemibrycon was proposed by Günther (1864), as a subgenus of Tetragonopterus Cuvier, differing by “cleft of the mouth of moderate width, and the entire edge of the maxillary denticulated”. Tetragonopterus polyodon Günther was designed as type species. Hemibrycon was extensively revised by Eigenmann (1927), whose accounts still constitute the single complete review of the genus. Publications on Hemibrycon subsequent to Eigenmann’s revision usually involve only descriptions of new species occurring in restricted geographic areas of South America (e.g., Bertaco et al., 2007; Román-Valencia & Arcila-Mesa, 2009). The genus still lacks a phylogenetic diagnosis, and is currently delimited based on Eigenmann (1917, 1927), as caudal fin naked, premaxillary with two series of teeth, inner series with four teeth, infraorbital 2 in contact with the lower limb of the preopercle, adipose fin present, anal fin moderate or long, gill rakers simple, teeth along the greater part or along the entire edge of the maxillary. However, none of the characters used are unique to the genus and most of them are plesiomorphic within Characidae or treated as putative synapomorphies of more inclusive clades containing Hemibrycon (Malabarba & Weitzman, 2003). Malabarba & Weitzman (2003) hypothesized Hemibrycon as belonging to a large monophyletic clade inside Characidae, Clade A, based on the putative derived presence of four teeth in the inner series of the premaxilla and reduced number of dorsal-fin rays (ii,8), also including the subfamily Glandulocaudinae (Glandulocaudinae and Stevardiinae sensu Weitzman et al., 2005) and the genera Attonitus Vari & Ortega, Boehlkea Géry, Bryconacidnus Myers, Bryconamericus Eigenmann, Caiapobrycon Malabarba & Vari, Ceratobranchia Eigenmann, Creagrutus Günther, Cyanocharax Malabarba & Weitzman, Hypobrycon Malabarba & Malabarba, Knodus Eigenmann, Microgenys Eigenmann, Monotocheirodon Eigenmann & Pearson, Odontostoechus Gomes, Othonocheirodus Myers, Piabarchus Myers, Piabina Reinhardt, Rhinobrycon Myers, and Rhinopetitia Géry. The group was latter expanded with the addition of Bryconadenus by Weitzman et al. (2005), Phallobrycon by Menezes et al. (2009), and Aulixidens and Nantis by Mirande (2009, 2010). Recent phylogenetic studies among characid fishes, involving the analysis of nuclear and mitochondrial genes (Calcagnotto et al., 2005; Javonillo et al., 2010), or osteology and external morphology (Mirande, 2009, 2010) have corroborated the hypothesis of the monophyly of Clade A including Hemibrycon. Mirande (2009, 2010) further redefined Clade A and elevated the rank of Stevardiinae to correspond to Clade A, instead of a section of it. Since no further decision was presented by Mirande (2009, 2010) regarding the tribes Corynopomini, Diapomini, Glandulocaudini, Stevardiini, and Xenurobryconini, or to which tribes should be referred the remaining Clade A genera, and due to the lack of evidence of non-monophyly of the tribes previously proposed, we will keep their use as internal monophyletic clades in Stevardiinae (sensu Mirande). Herein we review the Hemibrycon species occurring in the east of the Andean Cordilleras, redescribe nine species based in the analysis of their type series and additional specimens, and also describe two new species, one from río Madre de Dios basin and other from the upper río Ucayali basin, both in Peru. Material and Methods Counts were taken as described by Fink & Weitzman (1974), with the exception of number of scale rows below lateral line which were counted from the scale row ventral to lateral line to the scale row nearest the first pelvic-fin ray. Vertebral counts, supraneurals, gill rakers, teeth, and procurrent caudal-fin-ray counts were taken from cleared and stained specimens (c&s) prepared according to the method of Taylor & van Dyke (1985). The gill raker at the junction of the ceratobranchial and the epibranquial is included in the counting of gill rakers of lower limb. Maxillary tooth counts were also taken in specimens included in the tables. Vertebral counts were also taken in radiographs specimens (x-ray) and include the four vertebrae integrated in the Weberian apparatus and the terminal centrum, which was counted as one vertebra. Scanning electron micrographs (SEM) of teeth and jaws were taken from cleared and stained dissected specimens. Measurements were taken point-to-point with an electronic caliper on the left side of specimens when possible. All measurements other than SL are expressed as a percentage of SL except subunits of the head, which are recorded as a percentage of head length. Box plots of the anal-fin rays and lateral line counts were constructed with SigmaPlot 2.0 for Windows; basic descriptive statistics for meristic data follow Weitzman & Malabarba (1999). Morphometric data for the type series of each species and non-type specimens are presented separately in tables. Although this review deals only with Cis-Andean species, the diagnoses are compared to all species of the genus. Institutional abbreviations follow Reis et al. (2003), with the addition of the Instituto de Investigaciones Biológicas Alexander von Humboldt - Peces, Villa de Leyva, Boyacá V. A. Bertaco & L. R. Malabarba 739 (IAvH-P), and Departamaneto de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre (UFRGS). List of the examined specimens of each species includes in this order: catalog number; total number of specimens in that lot, followed by the number of c&s and/or x-ray specimens in parentheses when available, standard length range, sex for main types, collecting locality, coordinates, and date. Collectors are given for type series of each species when disponible. List of comparative material includes in this order: catalog number; total number of specimens in that lot (and number of c&s specimens in parentheses when available), and collecting locality. The synonymy provided for each species contains only papers that include taxonomic changes or and/or illustrate characters. Sex of adult specimens of Hemibrycon was recognized by visual examination of their gonads and/or by the presence or absence of the bony hooks in fin rays. For histological analyses, the gonads were obtained from specimens deposited in institutional fish collections, probably fixed in 10% formalin and stored in 70% ethanol prior to sectioning. Ovaries and testes were removed from one side, dehydrated in 99% ethanol, and infiltrated and embedded in glycol methacrylate. Saggital sections were made at 0.5 m with microtome, mounted on glass slides, and stained either with toluidine blue and alizarin-red. For scanning electron microscopy (SEM), the pieces of mature testes of some Hemibrycon species were dehydrated in ethanol series, dried in a critical point dryer, and scattered upon a carbon tape of the stub and viewed with a scanning electron microscope. Gill gland (Burns & Weitzman, 1996) observations in males and females were made through light microscopy under stereomicroscope. When verified the presence of a gill gland, the first gill arch from one side was removed, dehydrated in ethanol series and critical point dryer. The gill arch was fixed upon the stub with a carbon tape, coated with gold in a sputtercoater, and viewed with a scanning electron microscope (SEM). Results Hemibrycon beni Pearson, 1924 Fig. 1 Hemibrycon beni Pearson, 1924: 42-43 (original description; type material; type locality: Espia and río Colorado, lower Bopi, Bolivia), 62-63 (pl. 2, fig. 6, cotype). Diagnosis. Hemibrycon beni is readily distinguished from most congeners, except H. mikrostiktos, H. paez, H. tridens, and H. virolinica, by the number of branched anal-fin rays (15-19 vs. 20-34, Fig. 2). Hemibrycon beni differs from these species by the number of lateral line scales (44-53 vs. 40-42, 39-42, 39, and 40-44, respectively). Furthermore, H. beni differs from H. virolinica by the number of predorsal scales (17-20 vs. 10-15). The branched anal-fin ray counts of H. beni overlapping somewhat the H. helleri counts (15-19 vs. 19-23), but they can be distinguished further by the size of humeral spot (3-4 vs. 7-8 horizontal series of scales), and by total number of vertebrae (38-39 vs. 41-43). Description. Morphometric data for H. beni summarized in Table 1. Largest male 81.4 mm SL, largest female 34.3 mm SL. Body compressed and moderately elongate; greatest body depth usually at vertical through middle length of pectoral fins. Dorsal profile of head straight to slightly convex. Dorsal body profile convex from occipital bone to base of last dorsalfin ray; straight from this point to adipose-fin origin. Ventral profile of head convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through below middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two teeth rows; outer row with 4-5 tricuspid teeth with central cusp slightly longer; inner row with 4 pentacuspid teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla fully toothed, with 7-14 unito tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 3-5 cusps, followed by medium sized tooth with 3 cusps, and 8-9 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually. Dorsal-fin rays ii,8 (one with ii,7 and one with iii,8; n = 30); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin convex. Dorsal fin without bony hooks. Adipose-fin located at vertical through insertion of last or posterior to last anal-fin ray. Anal-fin rays iii-iv,16-18 (one with 15 and two with 19, mode = 17, n = 35, Fig. 2). Anal-fin profile slightly convex in males and nearly straight in females. Anal-fin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of small bony hooks along posterolateral border of each segment of lepidotrichia, usually along last unbranched ray and third to fourth branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-11 (mode = 10, n = 33). Pectoral-fin tip reaching pelvic-fin origin in all specimens. Pectoral fin without bony hooks. Pelvic-fin rays i,6,i (one with i,5,i, n = 33). Pelvicfin origin located 5-6 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one small bony hook per segment of lepidotrichia along ventromedial border of second to eighth branched rays. Caudal fin forked with 19 principal rays without bony hooks A review of the Cis-Andean species of Hemibrycon 740 (n = 33); lobes similar in size. Caudal-fin base with a few scales in half-length, followed by one large scale in each lobe. Caudal fin without bony hooks. Dorsal procurrent rays 10-11 and ventral procurrent rays 11 (n = 2, x-ray). Scales cycloid, moderately large. Lateral line complete with 44-53 (mode = 45, n = 32, Fig. 3). Scale rows between dorsalfin origin and lateral line 7-8 (mode = 8, n = 33); scale rows between lateral line and pelvic-fin origin 6-8 (mode = 7, n = 33). Predorsal scales 17-20, arranged in regular series (mode = 18, n = 33). Scales rows around caudal peduncle 16-18 (mode = 16, n = 32). Axillary scale on pelvic-fin origin extends posteriorly covering two scales. Scale sheath along anal-fin base with 5-8 scales in single series, extending to base of most anterior branched rays. Precaudal vertebrae 18-19; caudal vertebrae 20; total vertebrae 38-39 (n = 3). Supraneurals 7 (n = 1, x-ray). Gill rakers on upper limb of outer gill arch 6, and on lower limb 10-11 (n = 4). Color in alcohol. Dorsal portion of head and body dark brown. Dorsolateral portion of body with scattered black chromatophores. Midlateral body silvery. One small and vertical black humeral spot, located over third to fourth lateral line scales and extending over 1-2 horizontal series of scales including lateral line, and sometimes over the first horizontal series below lateral line. Base of caudal fin and middle rays black pigmented. Abdominal region almost devoid of black chromatophores. Dorsal, adipose, and caudal fin with dark brown pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Caudal peduncle without spot. Pectoral and pelvic fins hyaline (Fig. 1). Body yellowish. Sexual dimorphism. Males of Hemibrycon beni are easily recognized by the presence of bony hooks on the analand pelvic-fin rays. Males and females also slightly differ in body Fig. 1. Hemibrycon beni, CAS 44333, syntype, male, 56.0 mm SL, upper río Beni basin, Bolivia. Fig. 2. Tukey box plots of number of branched anal-fin rays in Hemibrycon species. Mean represented by thick vertical bar, and 25th and 75th percetiles as lateral borders of box plots. Number in parentheses = N. Fig. 3. Tukey box plots of number of lateral line scales in Hemibrycon species. Mean represented by thick vertical bar, and 25th and 75th percetiles as lateral borders of box plots. Number in parentheses = N. V. A. Bertaco & L. R. Malabarba 741 depth (Table 1), and in anal-fin shape, which is slightly convex in males and nearly straight in females. Gill glands were not found on first gill arch in either males or females. Distribution. Hemibrycon beni is known from río Beni drainage, upper río Madeira basin, where ríos La Paz and Miguilla join to form río Bopi, Espia, La Paz, Bolivia (Fig. 4). Remarks. Hemibrycon beni was described by Nathan Pearson based on specimens collected by the Mulford Expedition, Bolivia, in 1921. In the original description, Pearson designated 48 “cotypes” in good condition plus 58 “dried during shipment”, all specimens catalogued under IU 17321, and further listed six specimens not identified as types (IU 17347, now CAS 44335). Of the original 106 cotypes under IU 17321, however, there are 107 presently catalogued as cotypes under CAS 44333, 29 specimens, CAS 44334, 60 specimens, USNM 117543, 2 specimens, and UMMZ 66504, 16 specimens. This last lot was not examined. All specimens of the lot CAS 44334 are very dry but the remaining syntypes are in good condition. Material examined. Syntypes. CAS 44333, 29 (1 x-ray), 24.156.0 mm SL, CAS 44334, 60, 27.4-81.4 mm SL, USNM 117543, 2 (x-ray), 31.6-42.1 mm SL, where ríos La Paz and Miguilla join to form río Bopi, río Beni drainage, elev. 3,080 ft., Espia, La Paz, Bolivia, ca. 16º16’S 67º12’W, Jul 1921, N. E. Pearson. Non-type specimens. CAS 44335, 6, 22.5-24.8 mm SL, río Colorado, tributary to lower río Bopi 10 mi above Huachi, Mulford Exploration of the Amazon Basin, La Paz, Bolivia, ca. 16º05’S 67º12’W, Sep 1921. Hemibrycon helleri Eigenmann, 1927 Figs. 5-6 Hemibrycon helleri Eigenmann, 1927: 402 (in key), 406 (pl. 96, fig. 2; original description; type material; type locality: río Comberciato, río Urubamba drainage). Diagnosis. Hemibrycon helleri is distinguished from all congeners, except H. jelskii, by the size of humeral spot (over 7-8 vs. 3-6 horizontal series of scales). It differs from H. jelskii by the number of branched anal-fin rays (19-23 vs. 25-30, Fig. 2), H. beni H. helleri Syntypes Paratypes Non-types n Range Mean SD n Range Mean SD n Range Mean SD Standard length (mm) 30 29.0-81.4 45.5 - 8 36.4-78.6 53.9 - 11 43.3-81.6 60.9 - Percents of Standard length Predorsal distance 30 51.8-58.6 54.9 1.7 7 50.8-52.7 52.0 0.8 11 50.5-54.2 52.9 1.2 Prepelvic distance 30 41.2-51.0 45.9 1.9 7 43.1-47.9 44.9 1.5 10 42.9-47.0 45.4 1.1 Prepectoral distance 30 23.0-28.7 25.7 1.2 7 22.1-25.4 23.7 1.1 10 21.4-26.7 23.5 2.0 Preanal distance 30 60.9-67.8 63.3 1.6 7 59.2-61.2 60.2 0.9 11 57.9-63.9 61.4 1.8 Depth at dorsal-fin origin(m) 23 29.6-35.6 32.3 1.7 2 30.6-30.9 30.7 0.2 2 28.7-29.6 29.2 0.8 Depth at dorsal-fin origin(f) 7 29.4-33.1 31.2 1.1 6 29.3-34.5 32.1 1.8 8 28.5-32.4 30.8 1.4 Caudal peduncle depth 30 10.6-14.6 12.7 1.0 8 11.9-14.3 12.7 0.7 11 10.5-13.3 12.2 0.7 Caudal peduncle length 30 14.0-19.6 17.9 1.4 8 12.4-17.0 15.6 1.5 11 14.3-16.4 15.3 0.7 Anal-fin base 30 19.1-25.0 22.1 1.4 8 27.3-29.3 28.2 0.6 11 25.1-29.6 27.2 1.4 Dorsal-fin length 30 21.6-26.7 24.0 1.2 8 20.8-24.6 22.2 1.3 5 20.4-22.7 21.4 0.9 Pelvic-fin length (m) 23 14.8-18.2 16.3 0.9 2 11.8-13.0 12.4 0.8 2 13.1-13.3 13.2 0.1 Pelvic-fin length (f) 7 14.0-15.3 14.8 0.5 6 13.5-14.3 13.9 0.3 3 13.1-14.5 13.7 0.4 Pectoral-fin length (m) 23 18.8-22.1 20.4 0.8 2 18.7-20.2 19.4 1.0 2 20.2-20.2 20.2 0.0 Pectoral-fin length (f) 7 20.4-21.8 21.3 0.6 6 19.7-21.7 20.5 0.7 3 20.4-21.5 20.8 0.5 Head length 30 24.1-28.8 26.2 1.2 7 22.4-25.1 23.6 0.8 11 21.9-25.3 23.5 0.9 Percents of Head length Snout length 30 20.0-26.0 22.7 1.1 7 19.9-24.6 22.1 1.5 11 19.7-23.0 21.4 1.0 Upper jaw length 29 40.8-53.2 47.1 2.1 7 42.1-47.6 45.4 1.8 11 43.2-49.3 46.0 1.8 Orbital diameter 30 25.4-38.2 30.7 2.4 7 28.4-33.5 31.1 1.7 11 25.4-32.0 28.9 2.4 Interorbital width 30 29.1-35.3 31.9 1.3 7 30.9-33.7 32.2 1.1 11 30.5-38.3 33.9 2.1 Table 1. Morphometric data of syntypes of Hemibrycon beni (CAS 44333, 44334; USNM 117543) from río Beni basin, Espia, La Paz, Bolivia, and paratypes of Hemibrycon helleri (CAS 44354; FMNH 58439), and non-types from río Urubamba basin (ANSP 180775, 180777; CAS 70077). m, males; f, females. SD = Standard deviation. Fig. 4. Map of central and northern South America showing geographic distribution of Hemibrycon beni (1, solid hexagon), H. divisorensis (2, open triangle), H. helleri (3, ellipse), H. huambonicus (4, solid triangles), H. jelskii (5, solid dots), H. inambari (6, rectangles), H. metae (7, solid squares), H. mikrostiktos (8, open square), H. polyodon (9, inverted triangle), H. surinamensis (10, solid diamonds), H. taeniurus (11, Trinidad Island), H. tridens (12, open circle). Some symbols represent more than one lot or locality of specimens. 1-12 = type locality of each species. A review of the Cis-Andean species of Hemibrycon 742 and by the number of scales along anal-fin base scale sheath (6-12 vs. 13-28). Hemibrycon helleri is rather similar to H. inambari new species, but can be distinguished by the size of humeral spot (over 7-8 vs. 5-6 horizontal series of scales), number of predorsal scales (16-18 vs. 13-16), and by the total number of vertebrae (41-43 vs. 39-40). Description. Morphometric data for H. helleri summarized in Table 1. Largest male 78.6 mm SL, largest female 81.6 mm SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head straight to slightly convex. Dorsal body profile convex from occipital bone to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head nearly straight to slightly convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along analfin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two tooth rows; outer row with 3-5, tricuspid teeth with central cusp slightly longer; inner row with 4 tetrato pentacuspids teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla fully toothed with 8-14 unito tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3 cusps, and 7-9 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 6). Dorsal-fin rays ii,8 (n = 33); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin nearly straight to slightly concave. Males with bony hooks in distal one-third of first branched rays. Adipose-fin located at vertical through insertion of last or posterior to last anal-fin ray. Analfin rays ii-v,19-23 (mode = 21, n = 37, Fig. 2). Anal-fin profile slightly convex in males and nearly straight in females. Analfin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of small bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and twelfth to sixteenth branched rays. One male paratype had bony hooks in all analfin branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-11 Fig. 5. Hemibrycon helleri, ANSP 180775, female, 81.1 mm SL, upper río Ucayali basin, Peru. Fig. 6. Hemibrycon helleri, ANSP 180775, female, 66.6 mm SL. Scanning electron micrograph of right side upper and lower jaws. Scale bar = 1 mm. V. A. Bertaco & L. R. Malabarba 743 (mode = 10, n = 27). Pectoral-fin tip reaching pelvic-fin origin in males. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvic-fin rays i,6,i (n = 30). Pelvic-fin origin located 4-5 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one small bony hook per segment of lepidotrichia along ventromedial border of fourth to eighth branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 30); lobes similar in size. Caudal-fin base with a few scales in half-length, followed by one large scale in each lobe. Dorsal procurrent rays 8-10 and ventral procurrent rays 9-10 (n = 12). Scales cycloid, moderately large. Lateral line complete with 42-45 (mode = 42, n = 23, Fig. 3). Scale rows between dorsalfin origin and lateral line 7-8 (mode = 8, n = 35); scale rows between lateral line and pelvic-fin origin 5-6 (mode = 6, n = 35). Predorsal scales 15-18, arranged in regular series (mode = 16, n = 34). Scales rows around caudal peduncle 16-18 (mode = 16, n = 27). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 6-12 scales in single series, extending to base of most anterior branched rays. Precaudal vertebrae 19-21; caudal vertebrae 22-23; total vertebrae 41-43 (n = 12). Supraneurals 6-7 (n = 12). Gill rakers on upper limb of outer gill arch 6-7, and on lower limb 10-11 (n = 11). Color in alcohol. Type material discolored. Color based on the non-type specimens. General ground body color yellowish. Dorsal portion of head and body with dense concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. Midlateral body silvery. One large and vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 7-8 horizontal series of scales, including lateral line. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in the caudal peduncle. Abdominal region almost devoid of black chromatophores. Adipose fin densely black pigmented. Dorsal and caudal fin with black pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Pectoral and pelvic fins hyaline (Fig. 5). Sexual dimorphism. Males of Hemibrycon helleri are easily recognized by the presence of bony hooks on the dorsal-, pectoral-, analand pelvic-fin rays. Males and females also slightly differ in body depth (Table 1), and in anal-fin shape, which is slightly convex in males and nearly straight in females. Mature males with gill gland on first gill arch, covering the first branchial filaments (Fig. 7). Distribution. Hemibrycon helleri is known from río Comberciato, and río Urubamba, upper río Ucayali drainage, Cusco, Peru (Fig. 4). Remarks. Eigenmann (1927: 406) described Hemibrycon helleri and designated the holotype as “13565 Type” [MCZ 31565, the catalog number mistakely cited in the original description] and 17 paratypes (CM 7439, IU 13754) from río Comberciato, Peru. Later, Eigenmann & Allen (1942: 216) listed the type material but did not provided the catalog number for types of H. helleri, but listed 18 type specimens along with their lengths, and type locality. Böhlke (1953) in his catalog of types from Stanford University did not list types of H. helleri. Ibarra & Stewart (1987: 43) listed three paratypes of H. helleri but did not provide the catalog number of FMNH specimens. Eschmeyer (1998: 717) listed two possible lots as holotype, “?MCZ 31565” (1) or MCZ 30980 (1), and the following lots as paratypes: CAS 44354 [ex IU 13754] (5) and FMNH 58439 (3), followed posteriorly by Lima et al. (2003: 129); there are 8 paratypes missing. According to Eigenmann (1927) the holotype has 100 mm of size [total length - TL]. The specimen from MCZ 31565 measures 78.9 mm SL and 94.9 mm TL and the specimen from MCZ 30980 has 81.1 mm SL and 98.9 mm TL. Although the specimen from MCZ 30980 is larger and more close to the body size of the holotype mentioned by Eigenmann (100 mm TL), the specimen corresponding to the original catalog number referred as the holotype MCZ 31565 (mistyped 13565) has the same number of branched anal-fin rays of the specimen illustrated as the holotype in the figure 2 by Eigenmann (1927, plate 96), 23 vs. 22 branched anal-fin rays on specimen of lot MCZ 30980, and so we consider that the specimen available as MCZ 31565 is actually the holotype. Based on data and fish images taken from the lots MCZ 30980 (1), and MCZ 30981 (7) we can confirm that these specimens are part of the missing type series of H. helleri. The specimen listed as nontype by Eigenmann (1927: 406; CAS 44355, ex IU 17611) from río Crisnejas, Peru is actually a specimen of H. huambonicus. Material examined. Holotype. MCZ 31565, female (x-ray), 78.9 mm SL, río Comberciato, a small tributary of middle río Urubamba, 30 miles above the Pongo de Mainique, Cusco, Peru, 1,800 ft. elev., ca. 12º28’S 73º07’W, 1910-1915, E. Heller (Yale-National Geographic Expedition). Paratypes. CAS 44354, 5, 39.6-72.0 mm SL, FMNH 58439, 3 (x-ray), 36.4-78.5 mm SL, MCZ 30980, 1 (x-ray), 81.1 mm SL, MCZ 30981, 8 (x-ray), 46.1-79.2 mm SL, collected with the holotype. Non-type specimens. Peru, Cusco, río Urubamba drainage: ANSP 180775, 4 (1 c&s), 53.3-81.1 mm SL, quebrada Rosaríomayo, west of Quelluono on road to Kiteni, 12º46’28”S 72º39’06”W, 19 Jul 2004. ANSP 180777, 2, 20.4-72.4 mm SL, río Amaybamba, southeast of Quillabamba on road to Ollantaytambo, 12º59’55”S 72º31’24”W, 17 Jul 2004. ANSP 180780, 1, 23.5 mm SL, Yanayaku Grande, tributary of río Urubamba, southeast of Quillabamba on road to Ollantaytambo, 12º59’49”S 72º32’06”W, 17 Jul 2004. CAS 70077, 15, 27.5-81.5 mm SL, río de Santa Ana, creek entering middle río Urubamba at ca. 3000-3400 ft. elev., the farthest point reached by the Eigenmann’s on río Urubamba, ca. 12º52’S 72º43’W, 15 Nov 1918. Hemibrycon huambonicus (Steindachner, 1882) Figs. 8-9 Tetragonopterus huambonicus Steindachner, 1882: 177 (original description, type locality: Huambo [Peru]). Hemibrycon huambonicus. -Eigenmann, 1910: 432 (synonym of H. polyodon (Günther)). -Eigenmann, 1927: 402 (in key), 410-411 (redescription, and valid species). A review of the Cis-Andean species of Hemibrycon 744 Diagnosis. Hemibrycon huambonicus is distinguished from most of its congeners by the number of lateral line scales (4448 vs. 39-43 or 48-58, Fig. 3). From the species sharing similar lateral line counts, it differs from H. beni, and H. dentatus by the number of branched anal-fin rays (22-27 vs. 15-19 and 2834, respectively); from H. cairoense by the number of scale rows above lateral line (8-10 vs. 6-7); from H. helleri by the number of scales along anal-fin base scale sheath (17-26 vs. 612) and the number of scale rows above lateral line (8-10 vs. 78), from H. polyodon by the number of caudal peduncle scales (18-20 vs. 16), head length (22.0-26.0 vs. 20.9-22.9% SL), and upper jaw length (45.2-52.6 vs. 43.7-45.6% HL), and from H. raqueliae by the number of predorsal scales (15-19 vs. 10-13) and by the number of cusps of first maxillary tooth (3 vs. 5). Description. Morphometric data for H. huambonicus summarized in Table 2. Largest male 87.0 mm SL, largest female 109.9 mm SL. Body compressed and elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head nearly straight to slightly convex. Dorsal body profile convex from occipital bony to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head slightly convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin and straight to anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head heavy (massive) and relatively small. Mouth terminal, mouth slit nearly at horizontal through below middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Fig. 7. First gill arch showing gill gland. Lateral view of the left side of (a) Hemibrycon helleri, ANSP 180775, (b) Hemibrycon metae, USNM 228563; (c) Hemibrycon huambonicus, USNM 086794; (d) Hemibrycon jelskii, MCP 35022. Scale bars = 1 mm. V. A. Bertaco & L. R. Malabarba 745 Premaxilla with two tooth rows; outer row with 4-6, tricuspid teeth with central cusp slightly longer; inner row with 4 pentacuspid teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla almost fully toothed with 7-13 unito tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3-5 cusps, and 7-10 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 9). Dorsal-fin rays ii,8 (n = 64); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located approximately to middle of SL and posterior to vertical through pelvic-fin origin. Males with bony hooks in distal one-third of first branched rays. Profile of distal margin of dorsal fin nearly straight to slightly concave. Adipose-fin located at vertical through insertion of two last anal-fin rays. Anal-fin rays iii-v,2227 (mode = 24, n = 64, Fig. 2). Anal-fin profile slightly concave in males and nearly straight in females. Anal-fin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of developed bony hooks along posterolateral border of each segment of lepidotrichia, usually along last unbranched ray and first twelve branched rays. Only two males (syntype and non-type male) possess bony hooks in all anal-fin rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-12 (mode = 11, n = 64). Pectoral-fin tip surpassing pelvic-fin origin in males, and reaching in females. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvic-fin rays i,6,i or i,7 (n = 64). Pelvic-fin origin located 4-5 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one small bony hook per segment of lepidotrichia along ventromedial border of all branched rays. Caudal fin forked with 19 principal rays (n = 64); lobes in similar size. First third of caudal-fin scaled. Dorsal procurrent rays 11 and ventral procurrent rays 11-12 (n = 4). Scales cycloid, moderately large. Lateral line complete with 44-48 (mode = 45, n = 64, Fig. 3). Scale rows between dorsal-fin origin and lateral line 8-10 (mode = 9, n = 64); scale rows between lateral line and pelvic-fin origin 6-7 (mode = 7, n = 64). Predorsal scales 15-19, arranged in regular series (mode = 17, n = 62). Scales rows around caudal peduncle 18-20 (n = 64). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 17-26 scales in single series, extending to base to 18th to 24th branched rays. Precaudal vertebrae 20-21; caudal vertebrae 22-24; total vertebrae 42-43 (x-ray of syntype). Supraneurals 8-9. Gill rakers on upper limb of outer gill arch 7-8, and on lower limb 11-12 (n = 12). Color in alcohol. General ground body color brown yellowish. Dorsal portion of head and body with concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. One vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 5-6 horizontal series of scales, including lateral line. Caudal peduncle and middle caudal-fin rays dark pigmented. Abdominal region almost devoid of black chromatophores. Dorsal, adipose and caudal fin with dark pigmentation diffuse, and pectoral and pelvic fins hyaline (Fig. 8). H. huambonicus H. inambari Río Huallaga basin Río Marañon basin Río Madre de Dios basin S n Range Mean SD n Range Mean SD H n Range Mean SD Standard length (mm) 87.0 63 39.5-109.9 69.5 - 86 32.0-107.1 69.9 - 65.4 52 32.3-87.3 51.7 - Percents of Standard length Predorsal distance 52.5 63 26.4-54.9 51.0 3.5 86 45.6-55.2 50.6 1.9 51.9 52 48.6-54.8 52.0 1.4 Prepelvic distance 43.1 63 39.6-47.0 43.5 1.7 86 38.0-46.7 42.0 2.0 41.8 52 40.4-47.6 44.2 1.7 Prepectoral distance 22.9 63 21.7-27.3 23.9 1.1 86 19.8-25.9 22.2 1.2 21.2 52 19.9-25.9 23.1 1.5 Preanal distance 55.7 63 54.1-62.2 58.0 1.9 86 51.5-61.3 56.9 2.4 56.8 52 54.8-63.1 58.8 1.8 Depth at dorsal-fin origin (m) 32.2 16 29.7-34.1 31.4 1.4 41 27.3-32.6 29.5 1.2 31.1 14 29.1-32.7 31.2 1.0 Depth at dorsal-fin origin (f) - 47 28.9-35.8 32.0 1.5 43 29.3-34.9 31.8 1.1 - 38 28.7-35.3 32.0 1.4 Caudal peduncle depth 16.2 16 11.2-15.1 12.8 0.7 86 10.7-13.6 12.3 0.6 13.0 52 11.1-14.6 12.8 0.6 Caudal peduncle length 15.5 47 13.5-17.9 15.4 1.0 86 13.2-18.7 15.7 1.1 13.7 52 10.9-15.6 13.9 1.0 Anal-fin base 33.4 63 26.3-36.1 30.9 1.8 86 27.1-37.7 32.1 2.1 32.9 52 28.0-34.4 31.2 1.6 Dorsal-fin length 24.1 63 22.0-26.3 23.7 1.0 85 20.4-26.9 23.3 1.3 22.9 52 21.0-25.3 23.1 1.0 Pelvic-fin length (m) 16.2 16 14.1-17.3 15.2 0.8 42 14.2-17.4 15.7 0.7 12.3 14 11.2-13.8 12.3 0.6 Pelvic-fin length (f) - 47 12.7-17.0 14.5 0.9 44 12.7-15.8 14.2 0.7 - 38 11.2-13.6 12.7 0.6 Pectoral-fin length (m) 22.6 16 20.8-23.4 21.8 0.7 42 18.9-23.3 20.7 0.9 19.0 14 17.7-22.7 19.4 1.1 Pectoral-fin length (f) - 47 19.7-25.3 22.0 1.0 44 18.7-22.6 20.4 0.9 - 38 18.6-23.0 20.7 1.2 Head length 23.5 63 22.0-26.0 24.2 1.0 86 19.7-25.4 22.4 1.1 22.2 52 20.6-26.3 23.5 1.6 Percents of Head length Snout length 21.5 63 17.7-24.3 21.6 1.1 86 19.0-25.8 21.8 1.2 21.0 52 18.5-23.6 21.3 1.1 Upper jaw length 45.5 63 45.2-52.6 48.5 1.8 86 39.5-48.9 44.7 1.6 43.1 52 43.1-50.7 47.2 1.8 Orbital diameter 25.4 63 24.2-33.9 29.1 2.4 86 26.0-35.3 30.7 2.2 29.3 52 27.1-37.9 32.8 2.9 Interorbital width 35.5 63 31.0-39.2 34.5 1.7 86 28.1-39.2 33.7 2.1 33.1 52 29.3-36.2 33.1 1.4 Table 2. Morphometric data of syntype of Hemibrycon huambonicus (S, NMW 57531) from Huambo, Peru, non-types from the upper río Huallaga basin (CAS 70082, 70085, 70089, 70091-93; ICNMHN 7317), and from the upper río Marañon basin (CAS 70083, 70086; ROM 55238, 55406, 55366); and holotype (H, MUSM 35491) and paratypes of Hemibrycon inambari from the upper río Madre de Dios basin (ANSP 143290, 143293, 143307, 143291, 143294, 143300, 143306, 143312, 143317, 151478, 151497, 151526, MCP 45753, MUSM 26299, 26776, 26802, UFRGS 13201). The range includes the holotype. m, males; f, females. SD = Standard deviation. A review of the Cis-Andean species of Hemibrycon 752 Araza drainage, San Lorenzo, Camanti, Quispicanchi, Cusco, 13º13’02”S 70º31’48”W, 25 Oct 2005. ROM 66370, 9, 39.2-57.2 mm SL, Tambopata-Candamo Reserved Zone, Puno, left bank, large stream, 13º21’02”S 69º38’58”W, Tavara River tributary, 17 Aug 1992. Bolivia. Río Beni drainage: CAS 70079, 11, 46.9-82.2 mm SL, río Popoi, a tributary of upper río Beni, Beni, Sep 1921. CAS 70081, 18, 30.3-46.0 mm SL, 30 miles northwest of Rurrenabaque, Tumapasa, La Paz, ca. 14º10’S 67º30’W, Dec 1921. MNHN 1989.1417, 2, 50.7-59.1 mm SL, río San Juanito, Yacuma, Beni, ca. 15º10’S 67º04’W, Jul 1982. Río Chapare drainage: MCP 35019, 17, 42.1-66.8 mm SL, arroyo del Hotel el Puente, Villa Tunari, Chapare, Cochabamba, 16º59’06”S 65º24’45”W, 10 Nov 2003. MCP 35020 4, 37.4-57.7 mm SL, río Espiritu Santo, Villa Tunari, Chapare, Cochabamba, 16º58’20”S 65º24’48”W, 14 Sep 2002. MCP 35021, 10, 40.1-63.5 mm SL, río Espirito Santo, Chocolatal, Chapare, Cochabamba, 17º03’51”S 65º38’50”W, 20 Feb 2003. MCP 35022, 21, 36.3-46.0 mm SL, río Chipiriri, Chipiriri, Chapare, Cochabamba, 16º53’33”S 65º24’44”W, 20 Sep 2002. MNHN 1989.1418, 20, 35.375.5 mm SL, río Espirito Santo, Villa Tunari, Cristal Mayu, ca. 17º03’S 65º38’W, Jun 1983, L. Loubens. MZUSP 27827, 4, 53.773.0 mm SL, río Espirito Santo, Villa Tunari, Cristal Mayu, ca. 17º03’S 65º38’W, 24 Jun 1983. Brazil, rio Guaporé drainage: MCP 37754, 5, 26.0-36.1 mm SL, affluent of rio Galera, Pontes e Lacerda, Mato Grosso, 14º39’12”S 59º26’46”W, 12 Jul 2004. MCP 38177, 67 (5 c&s), 18.0-42.4 mm SL, stream Retiro at road BR 174, tributary of rio Guaporé, Nova Lacerda, Mato Grosso, 14º48’07”S 59º19’24”W, 12 Jul 2004. Hemibrycon metae Myers, 1930 Figs. 14-15 Hemibrycon metae Myers, 1930: 68-69 (original description; diagnosis; type locality: Guaiacaramo, río Guavio, Colombia). Hemibrycon dentatus metae. -Schultz, 1944: 362-363 (table 27; in key; new subspecies; non-type material examined). Diagnosis. Hemibrycon metae is distinguished from most of its congeners by the number of branched anal-fin rays (25-31 vs. 15-24, Fig. 2). From the species sharing similar branched anal-fin rays counts, it differs from H. boquiae by the number of caudal peduncle scales (16 vs. 14), and by the number of cusps of second tooth of premaxillary inner row teeth (7 vs. 5); from H. brevispini by the number of cusps of three anteriormost dentary teeth (5 vs. 3), and by absence of bony hooks in the caudal-fin rays (vs. presence); from H. cairoense by the number of lateral line scales (40-43 vs. 43-46), and by the number of cups of first dentary teeth (5 vs. 3); from H. dariensis by the absence of pigment in the distal tip of rays just above and below to middle caudal-fin rays; from H. dentatus, and H. huambonicus by the number of lateral line scales (40-43 vs. 44-50); from H. divisorensis and H. surinamensis by the absence of a wide black asymmetrical spot covering base of caudal-fin rays; from H. inambari by the of gill rakers (19-21 vs. 16-18) and by the number of scales along anal-fin base scale sheath (10-19 vs. 6-10); from H. jabonero by the number of caudal peduncle scales (16 vs. 14), and the number of scale rows below lateral line (5-7 vs. 45); from H. jelskii by the size of humeral spot (5-6 vs. 7-9 horizontal series of scales); from H. polyodon by the number of cusps of second tooth of premaxillary inner row teeth (7 vs. 5), caudal peduncle length (11.1-14.8 vs. 14.4-16.6% SL), and head length (22.1-25.0 vs. 20.9-22.9% SL); from H. quindos by the number of cusps of premaxillary inner row teeth (5-7 vs. 34); from H. raqueliae by the number of predorsal scales (1416 vs. 10-13) and by the number of cusps of first maxillary tooth (3 vs. 5); and from H. taeniurus by the number of cusps of second tooth of premaxillary inner row teeth (7 vs. 5), and by the humeral spot size (5-6 vs. 4-5 horizontal series of scales). Description. Morphometric data for H. metae summarized in Table 4. Largest male 79.7 mm SL, largest female 93.1 mm SL. Body compressed and moderately elongate; greatest body depth anterior to dorsal-fin origin. Dorsal profile of head slightly convex. Dorsal body profile convex from occipital bony to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head slightly convex. Ventral body profile convex from pectoral-fin origin to pelvicfin origin, and straight to slightly convex to anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two tooth rows; outer row with 4-5, trito pentacuspid teeth with central cusp slightly longer; inner row with 4 pentato heptacuspids teeth, gradually decreasing in length from first to third teeth and last smaller; central cusp twice or three times longer and broader than other cusps. Maxilla toothed with 6-11 unito pentacuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3-5 cusps, and 8-10 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 15). Dorsal-fin rays ii,8 (n = 104); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin nearly straight to slightly concave. Males with bony hooks in distal one-third of first branched rays. Adipose-fin located at vertical through insertion of last anal-fin rays. Anal-fin rays ii-vi,25-30 (one with 24 and two with 31, mode = 28, n = 104, Fig. 2). Analfin profile slightly concave in males and females. Anal-fin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of small bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and eighth to twelfth branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-13 (mode = 11, n = 104). Pectoral-fin tip surpassing pelvic-fin origin V. A. Bertaco & L. R. Malabarba 753 in males and nearly reaching in females. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvicfin rays i,6,i (three with i,7,i and two with i,6, n = 104). Pelvic-fin origin located 4-5 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing 1 small bony hook per segment of lepidotrichia along ventromedial border of second to eighth branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 104); lobes similar in size. Caudal-fin base have a few scales. Dorsal procurrent rays 11-12 and ventral procurrent rays 10-11 (n = 5). Scales cycloid, moderately large. Lateral line complete with 40-43 (mode = 42, n = 89, Fig. 3). Scale rows between dorsal-fin origin and lateral line 7-8 (mode = 8, n = 103); scale rows between lateral line and pelvic-fin origin 5-6 (rarely 7, mode = 6, n = 103). Predorsal scales 14-16, arranged in regular series (mode = 15, n = 94). Scales rows around caudal peduncle 16 (n = 96). Axillary scale on pelvic-fin origin extends posteriorly covering 2-4 scales. Scale sheath along anal-fin base with 10-19 scales in single series, extending to base of most anterior branched rays. Precaudal vertebrae 17-18; caudal vertebrae 22-24; total vertebrae 39-41 (n = 6). Supraneurals 6-8 (n = 6). Gill rakers on upper limb of outer gill arch 7-8, and on lower limb 12-13 (n = 19). Color in alcohol. Holotype discolored. General ground body color brown yellowish. Color based on the non-type specimens. General ground body color yellowish. Dorsal portion of head and body with concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. One large and vertical black humeral spot, located over third to fifth lateral line scales and extending over 5-6 horizontal series of scales, including lateral line. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in the caudal peduncle. Abdominal region almost devoid of black chromatophores. Dorsal and caudal fin with dark pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Pectoral, pelvic and adipose fins hyaline (Fig. 14). Sexual dimorphism. Males of Hemibrycon metae are easily recognized by the presence of bony hooks on the dorsal-, pectoral-, analand pelvic-fin rays. Males and females also slightly differ in pectoraland pelvic-fin lengths, and body depth (Table 4). Mature males with gill gland on first gill arch, covering the first branchial filaments (Fig. 7). Distribution. Hemibrycon metae is known from río Orinoco basin, Venezuela and Colombia, and Caribbean coastal basins of Venezuela (Fig. 4). Remarks. Hemibrycon metae was proposed by Myers (1930) from río Guavio, río Meta drainage, Guaiacaramo, Colombia based only in the holotype. We have compared the populations from río Meta and río Apure, two large rivers from río Orinoco basin, and did not find differences in meristic and morphometric characters. Fig. 14. Hemibrycon metae, INHS 61270, female, 61.4 mm SL, río Apure basin, Venezuela. Fig. 15. Hemibrycon metae, MCNG 17030, female, 39.8 mm SL. Scanning electron micrograph of right side upper and lower jaws. Scale bar = 1 mm. A review of the Cis-Andean species of Hemibrycon 754 In this study some Hemibrycon populations were identified from small coastal river basins in the Golfo de Paria, Venezuela. All these specimens do not exceed 51.3 mm SL, being smaller than río Orinoco specimens, and difficult to compare regarding body measurements. In relation to scales and maxillary tooth number, this population is more similar to H. metae than H. taeniurus from Trinidad Island. Samples of large specimens from coastal basins of Venezuela are necessary to confirm whether those populations are indeed conspecific. However, we tentatively assign the examined specimens from that area to H. metae. Material examined. Holotype. CAS 123727 (ex-SU 23727), female (x-ray), 77.2 mm SL, at junction of río Guavio and río Upía, río Meta drainage, río Orinoco basin, Guaiacaramo, Colombia, ca. 04º43’N 73º02’W, Jan 1928, H. A. Maria. Nontype specimens. Colombia. Meta, río Meta drainage: IAvH-P 2973, 7, 53.1-76.0 mm SL, quebrada Palmicha, afluente del río Unete, Casanare, ca. 05º10’N 72º30’W, 1 Aug 1984. IAvH-P 3122, 10, 47.6-93.0 mm SL, quebrada Chichaca afluente del río Cachiza, Aguazul, Casanare, ca. 05º15’N 72º29’W, 1 Mar 1994. IAvH-P 3322, 10, 51.3-70.0 mm SL, quebrada Guamalera, Yopal, Casanare, ca. 05º21’N 72º23’W, 1 Aug 1993. IAvH-P 3628, 25, 45.0-70.6 mm SL, río Unete, Casanare, ca. 05º10’N 72º30’W, 1 Aug 1993. IAvH-P 3632, 65, 45.0-86.8 mm SL, ríos Tocaria, Charte and Cravo Sur drainages, ca. 05º20’N 72º20’W, 18 Aug 1995. NRM 23991, 1, 48.8 mm SL, caño Candelaria tributary to río Negro, ca. 20 km SW of Villavicencio, ca. 04º5’N 73º42’W, 10 Jan 1988. NRM 23993, 1, 67.3 mm SL, caño Union tributary to río Ocoa, where crossed by road Villavicencio - Acacias, ca. 04º00’N 73º43’W, 6 Jan 1988. Venezuela. Río Orinoco basin, río Apure drainage: INHS 27766, 30 of 51, 29.4-45.8 mm SL, caño Curito at Ruta 5, Barinas, 07º58’41”N 71º00’05”W, 7 Jan 1992. INHS 31851, 12, 27.0-44.5 mm SL, río La Yuca 17 km N Barinas, Barinas, 08º46’00”N 70º15’00”W, 31 Dec 1993. INHS 61270, 22 of 28, 30.7-61.4 mm SL, río Santa Barbara 3 km NE Santa Barbara, Barinas, 07º50’14”N 71º11’14”W, 7 Jan 1992. MCNG 98, 10 of 27, 34.4-43.9 mm SL, 1 km al S carretera 5, via Cd Bolivia, Barinas, 08º20’8”N 70º31’04”W, 13 Jun 1979. MCNG 5646, 17 of 54, 29.5-47.0 mm SL, río Tucupido en Las Canoas, Portuguesa, 09º03’00”N 70º05’30”W, 18 Mar 1982. MCNG 6759, 23 of 73 (3 c&s), 25.5-49.5 mm SL, río Tinaco, carretera entre Tinaco y Tinaquillo, entre San Carlos e Valencia, Cojedes, Tinaco, 09º48’10”N 68º23’50”W, 3 Feb 1982. MCNG 7923, 12 of 64 (2 c&s), 44.5-71.6 mm SL, caño Grande en Finca Cano Grande, Barinas, Pedraza, 08º24’10”N 70º39’25”W, 7 Dec 1982. USNM 121466, 18, 35.6-50.5 mm SL, río Guárico and tributaries between San Sebastian and San Casemiro, Aragua, ca. 09º57’N 67º11’W, 12 May 1942. USNM 121467, 12 of 117, 42.7-72.8 mm SL, río Torbes, 1 km above Táriba, Tachira, ca. 07º40’N 72º15’W, 31 Mar 1942. Golfo de Paria coastal basin: USNM 228563, 16 of 21, 38.3-52.4 mm SL, Sucre, Clavellino reservoir Sucre, 29 Sep 1979. MCNG 17030, 20 of 58 (3 c&s), 27.349.2 mm SL, Sucre, Benitez, El Pilar, río Pilar, ca. 10º32’N 63º08’W, 28 Aug 1984. MCNG 17035, 20 of 76 (3 c&s), 30.0-46.9 mm SL, Sucre, Libertador, caño 20 km E de El Pilar, ca. 10º35’N 63º04’W, 28 Aug 1984. MCNG 16796, 10 of 19, 30.3-50.2 mm SL, Sucre, Benitez, caño 3 km S de El Pilar, ca. 10º30’N 63º07’W, 29 Aug 1984. CAS 70096, 58, 35.0-64.9 mm SL, Miranda, río Tiquirito at Concejo, a tributary of the Tuy River, 1 Aug 1918. FMNH 105860, 52, 21.446.7 mm SL, Venezuela, Monagas, río Azuma at edge of municipio Punceres on road to Caripito, 8 Aug 1985. MNHN 1920.0002, 1, 67.4 mm SL. Hemibrycon mikrostiktos, new species Figs. 16-17 Holotype. MUSM 35490, 44.4 mm SL, río Aguaytía, río Negro, upper río Ucayali basin, Aguaytía, Padre Abad, Ucayali, Peru, 09º02’34”S 75º30’45”W, 2 Nov 1999, P. de Rham & F. Chang. Paratypes. MCP 44521, 10 (3 c&s), 27.6-42.4 mm SL; MUSM 15845, 19 measured and counted of 187, 24.5-42.4 mm SL; UFRGS 12003, 10, 30.9-36.0 mm SL, collected with the holotype. Diagnosis. Hemibrycon mikrostiktos is readily distinguished from all congeners by the size of the humeral spot (2-3 vs. 4-9 horizontal series of scales), number of scale rows below of the lateral line (3-4 vs. 4-8), and total number of pelvic-fin rays (7 vs. 8). Furthermore, H. mikrostiktos differs from most congeners by the number of branched anal-fin rays (18-21 vs. 21-34, and 17 in H. tridens, Fig. 2), except H. beni and H. helleri. It differs from H. beni and H. helleri by the number of lateral line scales (40-42 vs. 44-53 and 42-44, Fig. 3). Description. Morphometric data for Hemibrycon mikrostiktos summarized in Table 4. Largest specimen 44.4 mm SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head nearly straight. Dorsal body profile convex from occipital bony to dorsal-fin origin; posteroventrally slanted at dorsal-fin base; straight from last dorsal-fin ray to adiposefin origin. Ventral profile of head convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along analfin base posterodorsally slanted. Caudal peduncle short, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head relatively small. Mouth terminal, mouth slit nearly at horizontal through below middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45o to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two tooth rows; outer row with 4-6, tricuspid teeth with central cusp slightly longer; inner row with 4 pentacuspid teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla toothed with 7-11 trito pentacuspid teeth, except for last three or four conical teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3 cusps, and 12-13 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 17). Dorsal-fin rays ii,8 (n = 20); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. First dorsal-fin pterygiophore V. A. Bertaco & L. R. Malabarba 755 inserted between the neural spines of eleventh to twelfth vertebrae (n = 3). Profile of distal margin of dorsal fin convex. Adipose-fin located at vertical through insertion of last or posterior to last anal-fin ray. Anal-fin rays iii-iv,18-20 (two with 21, mode = 19, n = 20, Fig. 2). Anal-fin profile slightly concave in all specimens. First anal-fin pterygiophore inserted between the haemal spine of last precaudal vertebra and the first caudal vertebrae. Anal-fin origin approximately at vertical through insertion in the middle dorsal fin. Pectoral-fin rays i,9-10 (mode = 9, n = 20). Pectoral-fin tip reaching pelvic-fin origin. Pelvic-fin rays i,5,i (n = 15) or i,6 (n = 5). Pelvic-fin origin located 3-4 predorsal scales anterior to vertical through dorsal-fin origin. Caudal fin forked with 19 principal rays (n = 20); lobes similar in size. Basal portion of caudal-fin lobes covered with irregular scales and smaller than those of the body, following by one larger scale in each lobe. Dorsal procurrent rays 12-13 and ventral procurrent rays 12-14 (n = 3). Scales cycloid, moderately large. Lateral line complete with 40-42 (mode = 41, n = 16, Fig. 3).[ Scale rows between dorsalfin origin and lateral line 6-7 (mode = 6, n = 18); scale rows between lateral line and pelvic-fin origin 3-4 (mode = 4, n = 18). Predorsal scales 14, arranged in regular series (n = 18). Scales rows around caudal peduncle 14 (n = 18). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 7-10 scales in single series, extending to base of most anterior branched rays. Precaudal vertebrae 17; caudal vertebrae 23-24; total vertebrae 40-41. Supraneurals 6-7 (n = 3). Gill rakers on upper limb of outer gill arch 5-6, and on lower limb 9-10 (n = 5). Color in alcohol. Dorsal portion of head and body with dense concentration of black chromatophores. Dorsal and dorsolateral portion of caudal peduncle near caudal fin base densely pigmented. Dorsolateral portion of body with scattered black chromatophores. Snout and upper portion of maxilla densely pigmented. Infraorbitals and opercle with scattered black chromatophores. Midlateral body silvery and dark pigmented. One small black humeral spot, located over third to fourth lateral line scales and extending over 1-2 horizontal series of scales, sometimes including lateral line. Base of caudal fin and middle rays black pigmented. Abdominal region almost devoid of black chromatophores. Dorsal, adipose, anal and caudal fin with dark pigmentation diffuse. Pectoral and pelvic fins hyaline (Fig. 16). Sexual dimorphism. None of the type specimens examined had hooks on fins or any other apparent sexually dimorphic features. Gill glands were not found on first gill arch. Distribution. Hemibrycon mikrostiktos is known from río Aguaytía, upper río Ucayali drainage, Ucayali, Peru (Fig. 4). Fig. 16. Hemibrycon mikrostiktos, MUSM 35490, holotype, 44.4 mm SL, upper río Ucayali basin, Peru. Fig. 17. Hemibrycon mikrostiktos, MCP 44521, paratype, female, 35.7 mm SL. Scanning electron micrograph of left side upper and lower jaws. Scale bar = 1 mm. A review of the Cis-Andean species of Hemibrycon 756 Etymology. The name mikrostiktos is from the Greek, mickros, small, and stiktos, spot, referring to the small humeral spot. A noun in apposition. Hemibrycon polyodon (Günther, 1864) Figs. 18-20 Tetragonopterus (Hemibrycon) polyodon Günther, 1864: 330 (original description; type locality: Guayaquil [río Pastaza basin, río Marañon drainage, upper rio Amazonas basin, Ecuador - see Remarks below]). Hemibrycon polyodon. Eigenmann, 1909: 313 (listed, Guayaquil). -Román-Valencia et al., 2007: 184 (diagnose and redescription). Hemibrycon coxeyi Fowler, 1943: 1-3, fig. 1 (original description; holotype: ANSP 70155; type locality: Hacienda Las Mascota, mouth of the río Pastaza, drainage of the Marañon, Ecuador). [NEW SYNONYM] Hemibrycon pautensis Román-Valencia, Ruiz-C. & Barriga, 2006: 212 (original description; type locality: río Paute en la desenbocadura del río Namangoza, cuenca del Amazonas, provincia de Morona-Santiago, Ecuador). [NEW SYNONYM] Diagnosis. Hemibrycon polyodon is distinguished from most of its congeners by the number of branched anal-fin rays (2428 vs. 15-24 or 28-34, Fig. 2). From the species sharing similar lateral line counts, it differs from H. boquiae by the number of scale rows above and below lateral line (8 and 6 vs. 6-7 and 4-5, respectively), and by the number of predorsal scales (15-17 vs. 12-15); from H. brevispini and H. cairoense by the number of scale rows above lateral line (8 vs. 6-7); from H. dariensis, H. divisorensis, H. surinamensis and H. taeniurus by the number of lateral line scales (42-45 vs. 39-42, Fig. 3); from H. huambonicus by the number of caudal peduncle scales (16 vs. 18-20), head length (20.9-22.9 vs. 22.0-26.0% SL), and upper jaw length (43.7-45.6 vs. 45.2-52.6% HL); from H. inambari by the number of scales along anal-fin base scale sheath (14-23 vs. 610); from H. jabonero by the number of caudal peduncle scales (16 vs. 14), and number of scale rows below lateral line (6 vs. 45); from H. jelskii by the number of maxillary teeth (7-10 vs. 817), and by the size of humeral spot (6-7 vs. 7-9 horizontal series of scales); from H. metae by the number of cusps of second tooth of premaxillary inner row teeth (5 vs. 7), caudal peduncle length (14.4-16.6 vs. 11.1-14.8% SL), and head length (20.9-22.9 vs. 22.1-25.0% SL); from H. quindos by the number of scale rows above and below of lateral line (8 and 6 vs. 6-7 and 4-5); from H. rafaelense by the number of predorsal scales (15-17 vs. 10-13), orbital diameter (29.5-34.1 vs. 36.6-43.6% HL), and interorbital width (32.1-35.3 vs. 34.7-41.5% HL); and from H. raqueliae and H. yacopiae by the number of predorsal scales (15-17 vs. 10-14), and by the number of cusps of first maxillary tooth (3 vs. 5 in H. raqueliae). Furthermore, H. polyodon can be distinguished from H. surinamensis and H. divisorensis by the absence of a wide black asymmetrical spot covering base of caudal-fin rays, and from H. dariensis by the absence of pigment in the distal tip of rays just above and below to middle caudal-fin rays. Description. Morphometric data for H. polyodon summarized in Table 5. Largest male 74.9 mm SL, largest female 69.5 mm SL. Body compressed and moderate elongate; greatest body H. metae H. mikrostiktos Río Meta basin Río Apure basin Río Ucayali basin H n Range Mean SD n Range Mean SD H n Range Mean SD Standard length (mm) 77.2 43 51.3-93.1 67.5 - 97 32.4-76.7 44.5 - 44.4 12 32.7-44.4 36.8 - Percents of Standard length Predorsal distance 50.8 43 47.4-53.3 50.6 1.4 97 48.4-56.2 52.5 1.4 52.8 12 52.1-55.2 53.6 1.0 Prepelvic distance 42.2 43 39.8-45.3 42.0 1.3 97 37.9-49.3 43.9 1.5 43.9 12 43.6-45.7 44.8 0.7 Prepectoral distance 22.5 43 21.0-24.6 22.7 0.7 97 21.7-26.2 23.6 0.9 23.1 12 23.1-25.2 24.1 0.6 Preanal distance 58.4 43 53.3-60.7 57.1 1.9 97 54.7-62.1 58.1 1.6 58.9 12 56.5-60.5 59.1 1.1 Depth at dorsal-fin origin (m) - 19 26.4-31.5 29.9 1.2 27 25.6-33.4 28.4 1.8 - - - - - Depth at dorsal-fin origin (f) 33.5 24 29.4-37.0 32.5 1.7 70 25.6-36.5 31.5 2.2 32.4 12 30.0-33.6 31.6 1.3 Caudal peduncle depth 12.4 43 10.6-12.5 11.5 0.5 97 9.5-13.0 10.8 0.6 12.4 12 11.0-13.6 12.2 0.8 Caudal peduncle length 13.5 43 10.7-15.3 13.2 1.0 97 11.1-14.9 12.9 0.8 15.9 12 13.6-19.3 16.8 1.4 Anal-fin base 33.2 43 31.4-37.7 34.6 1.3 97 30.4-36.4 33.2 1.1 28.2 12 26.6-30.4 28.0 1.1 Dorsal-fin length 22.6 43 21.6-26.6 24.0 1.1 97 19.0-27.6 24.0 1.1 23.4 12 22.8-25.6 23.7 0.7 Pelvic-fin length (m) - 19 13.4-16.5 14.7 0.9 27 13.0-15.6 14.4 0.7 - - - - - Pelvic-fin length (f) 14.0 24 13.0-15.2 14.1 0.6 70 12.7-16.3 14.1 0.7 13.6 12 13.0-14.6 13.8 0.5 Pectoral-fin length (m) - 19 18.8-25.8 21.5 1.6 27 19.5-22.0 21.0 0.6 - - - - - Pectoral-fin length (f) 21.2 24 19.5-23.6 21.1 1.0 70 18.6-22.8 21.3 0.8 22.1 12 20.7-23.7 22.1 0.7 Head length 21.4 43 20.4-23.6 21.6 0.7 97 21.4-25.0 23.2 0.8 23.8 12 23.7-25.8 24.8 0.7 Percents of Head length Snout length 24.9 43 20.2-24.4 22.0 0.9 97 18.3-24.3 22.1 1.1 21.3 12 19.3-22.9 20.9 1.0 Upper jaw length 45.3 43 40.9-46.5 43.6 1.4 96 40.8-50.3 45.4 1.7 50.2 12 44.5-50.2 47.7 1.7 Orbital diameter 28.7 43 26.0-34.5 31.1 1.8 97 26.8-38.7 34.2 1.8 33.2 12 33.2-37.6 35.7 1.1 Interorbital width 33.1 43 30.3-35.9 32.7 1.2 97 29.6-34.7 32.4 1.1 34.1 12 32.7-35.6 34.1 0.8 Table 4. Morphometric data of holotype (H) of Hemibrycon metae (CAS 123727), and non-types from río Meta basin, Colombia (IAvHP 2973, 3122, 3322, 3628, 3632), and from río Apure basin, Venezuela (INHS 27766, 31851, 61270; MCNG 98, 5646, 6759, 7923; NRM 23991, 23993), all from río Orinoco basin; and holotype (MUSM 35490) and paratypes (MCP 44521, MUSM 15845, UFRGS 12003, all unsexed) of Hemibrycon mikrostiktos from the upper río Ucayali basin, Peru. m, males; f, females. SD = Standard deviation. V. A. Bertaco & L. R. Malabarba 757 depth at vertical through middle length of pectoral fins. Dorsal profile of head slightly convex. Dorsal body profile convex from occipital bony to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head nearly straight to slightly convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two tooth rows; outer row with 3-5, tricuspid teeth with central cusp slightly longer; inner row with 4 trito pentacuspids teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla fully Fig. 18. Hemibrycon polyodon, BMNH 1858.7.25.41, holotype, female, 70.4 mm SL, Guayaquil, Ecuador. Fig. 19. Hemibrycon polyodon, KU 20004, male, 71.2 mm SL, río Pastaza basin, Ecuador. Fig. 20. Hemibrycon polyodon, KU 20004, female, 52.5 mm SL. Scale bar = 1 mm. A review of the Cis-Andean species of Hemibrycon 758 toothed with 7-10 unito tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3-5 cusps, and 7-9 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 20). Dorsal-fin rays ii,8 (n = 15); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located approximately to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin nearly straight. Males with bony hooks in distal one-third of first to fifth branched rays. Adipose-fin located at vertical through insertion of two last anal-fin rays. Anal-fin rays iiiv,24-28 (one with 24 and one with 28, mode = 26, n = 14, Fig. 2). Anal-fin profile convex in males and nearly straight in females. Anal-fin origin approximately at vertical through middle dorsal-fin base. Anal-fin rays of males bearing one pair of developed bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and all branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-12 (mode = 11, n = 15). Pectoral-fin tip reaching pelvic-fin origin in males. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvic-fin rays i,6,i (n = 15). Pelvic-fin origin located 5-6 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one developed bony hook per segment of lepidotrichia along ventromedial border of all branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 15); lobes similar in size. Caudal-fin base with few scales. Dorsal procurrent rays 12 and ventral procurrent rays 11 (n = 2). Scales cycloid, moderately large. Lateral line complete with 42-45 (mode = 45, n = 14, Fig. 3). Scale rows between dorsalfin origin and lateral line 8 (n = 15); scale rows between lateral line and pelvic-fin origin 6 (n = 15). Predorsal scales 15-17, arranged in regular series (mode = 16, n = 13). Scales rows around caudal peduncle 16 (n = 14). Axillary scale on pelvicfin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 14-23 scales in single series, extending to base of 15th to 24th branched rays. Precaudal vertebrae 18-19; caudal vertebrae 22-24; total vertebrae 40-43. Supraneurals 7-9. Gill rakers on upper limb of outer gill arch 7-8, and on lower limb 11-13 (n = 5). Color in alcohol. The holotype is discolored, except for the middle caudal-fin rays (Fig. 18). Color based on the non-type specimens. General ground body color yellowish. Dorsal portion of head and body with concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. Midlateral body silvery. One large and vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 6-7 horizontal series of scales, including lateral line. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in caudal peduncle. Abdominal region almost devoid of black chromatophores. Dorsal, caudal, and anal fins with scattered black chromatophores. Pectoral, pelvic and adipose fins hyaline (Fig. 19). Sexual dimorphism. Males of Hemibrycon polyodon are easily recognized by the presence of bony hooks on the dorsal-, pectoral-, analand pelvic-fin rays. Males and females also slightly differ in pectoraland pelvic-fin lengths (Table 5) and in anal-fin shape, which is convex in males and nearly straight in females. Gill glands were not found on first gill arch in either males or females. Distribution. Hemibrycon polyodon is known from the río Pastaza, río Marañon drainage, and upper río Amazonas basin, Ecuador (Fig. 4). Remarks of Hemibrycon polyodon. Günther (1864) described Tetragonopterus polyodon based on a single specimen from Guayaquil, Ecuador. Eigenmann (1927: 409-410) in his revision of the genus, assigned the distribution of H. polyodon as “Coastal streams of Ecuador”, also stated that “It is more than probable that the types were shipped from Guayaquil but were collected at a considerable elevation in the interior of Ecuador or Peru”. Recently, Román-Valencia et al. (2007) redescribed H. polyodon based in the digital image of holotype and some additional specimens from Santiago and Morona River basins. They furnished an insufficient diagnose for the recognition of the species, and the characters described in their diagnosis H. polyodon H. tridens Non-types H n Range Mean SD H Standard length (mm) 69.5 7 45.7-78.3 64.1 - 51.5 Percents of Standard length Predorsal distance 51.5 7 49.5-51.5 50.6 0.8 49.9 Prepelvic distance 40.6 7 39.9-41.9 40.7 0.8 39.5 Prepectoral distance 23.5 7 21.0-23.5 22.2 0.6 22.3 Preanal distance 55.7 7 53.7-58.0 55.7 1.9 57.0 Depth at dorsal-fin origin (m) - 4 27.7-33.8 30.1 2.6 23.6 Depth at dorsal-fin origin (f) 30.6 3 26.0-30.6 28.3 1.7 - Caudal peduncle depth 11.7 7 11.0-12.9 11.6 0.7 7.7 Caudal peduncle length 16.1 7 14.4-16.6 15.5 1.0 19.1 Anal-fin base 29.3 7 29.3-35.9 32.8 2.0 23.7 Dorsal-fin length 22.3 7 21.7-24.9 22.9 1.3 23.7 Pelvic-fin length (m) - 4 13.1-15.5 14.7 1.0 18.2 Pelvic-fin length (f) 14.7 3 13.2-14.7 13.7 0.6 - Pectoral-fin length (m) - 4 19.9-21.3 20.6 0.7 21.7 Pectoral-fin length (f) 21.2 3 19.0-21.2 20.3 1.2 - Head length 22.2 7 20.9-22.9 21.8 0.8 23.4 Percents of Head length Snout length 22.5 7 20.7-23.5 22.0 1.0 22.0 Upper jaw length 45.4 7 43.7-45.6 44.6 0.8 44.4 Orbital diameter 33.2 7 29.5-34.1 32.0 1.8 33.6 Interorbital width 32.1 7 32.1-35.3 33.9 0.9 28.6 Table 5. Morphometric data of holotype (H) of Hemibrycon polyodon (BMNH 1858.7.25.41) from Guayaquil, Ecuador, and non-types from tributary of río Pastaza, río Marañon basin (KU 19978, 19992, 20004), and of holotype of Hemibrycon tridens (CAS 44358) from rio Apurimac, upper río Ucayali basin, Curuhuasi, Peru. m, males; f, females. SD = Standard deviation. V. A. Bertaco & L. R. Malabarba 759 [“aleta dorsal con radios simples y ramificados de igual longitud, una mancha humeral estrecha y verticalmente alargada que alcanza una horizontal trazada desde el borde inferiror del opérculo”] were not found in our analysis of the holotype and non-type specimens of H. polyodon. Also, the authors commented that the supraorbital bone is found in this species, as well as other Hemibrycon species, but this bone is absent in all species of Hemibrycon we have examined (see discussion in Bertaco et al., 2007). Remarks of Hemibrycon coxeyi. The holotype of Hemibrycon coxeyi is badly preserved, lacking several body scales, with dorsal fin and snout broken, and body completely discolored. Only some measurements were taken, as fins length (except dorsal fin), body and caudal peduncle depth, and caudal peduncle length. All scales and fin ray counts were taken, except for the count of anal-fin scale sheath. Fowler (1943: 2) described H. coxeyi based on one of three specimens collected by Mr. W. Judson Coxey in 1931 in Ecuador. The author provided the exact locality according to Coxey trip: “All these specimens are from the basin of the Río Pastaza, in Tungurahua, where he spent some time on the river at the Hacienda Las Mascota”. Fowler recognized that H. coxeyi was nearly related to H. polyodon from the Pacific slope of Ecuador, but he was unable to identify the new species as H. polyodon based on Günther’s description. Böhlke (1958: 24-25) doubted the type locality of H. coxeyi reported by Fowler (“Hacienda Las Mascota, mouth of the Rio Pastaza, basin of the Rio Maranon, Ecuador”) and in footnote cited a reference to the location: “Annals Entomol. Soc. America, vol. 34, no. 4, Dec. 1941, p. 848”. According to Böhlke, this reference places Hacienda Las Mascota at a point far removed from mouth of the Pastaza (01º25’S 78º11’W), a station occupied on several occasions for some length of time by Coxey. The exact location of mouth of the río Pastaza is about 04º52’S 76º21’W according to Böhlke and current maps. Latter, Géry (1962: 66) discussing about the distribution of the known forms of Hemibrycon, commented that H. coxeyi is probably a synonym of H. huambonicus, and H. polyodon comes very probably from the same area of these species. According to Lima et al. (2003) the type locality should be amended to “Ecuador, Napo-Pastaza, Hacienda Mascota, río Topo, a tributary of río Pastaza, 01º25’S 78º11’W. The type localities of H. polyodon and H. coxeyi were inexact, but can be in some place of río Pastaza drainage, a relatively large tributary to the left margin of río Marañon, upper río Amazonas basin, in Ecuador. A comparison of the holotypes of H. polyodon and H. coxeyi, and new specimens from río Pastaza drainage failed to reveal any differences in examined meristic and morphometric features or other characters. Hemibrycon coxeyi is, therefore, considered a junior synonym of H. polyodon, an action previously suggested by Géry (1962). Remarks of Hemibrycon pautensis Román-Valencia, RuizC. & Barriga, 2006. Hemibrycon pautensis was described by Román-Valencia et al. (2006) based on specimens collected in río Paute, a tributary of the río Santiago drainage, río Marañon drainage, Ecuador. The río Santiago is nearly located to río Pastaza, both affluents of left margin of río Marañon drainage, in Peru and Ecuador, where also occurs Hemibrycon polyodon. In the original description, one of the characters presented in the diagnosis, the presence of six to seven branched dorsal-fin rays in H. pautensis was not found in the species of Hemibrycon analyzed in this study, as well as in any other Stevardiinae (sensu Mirande, 2009, 2010). Another character used by those authors in the diagnosis of the species, the number of branched anal fin rays (27-28), can be easily found in several species of the genus that were not compared in the diagnosis of their new species. Moreover, the authors presented different values along the text and table for counts of branched rays of anal-fin (27-28 and 25-28) and dorsal-fin (7-8 and 8-9), and number of maxillary teeth (7-11 and 9-11) for that species, respectively. Furthermore, the authors referred to the presence of a supraorbital bone in H. pautensis, and other Hemibrycon species, but this bone is absent in all species of Hemibrycon examined (Bertaco et al., 2007). Analyzing the characters presented in the diagnosis and in the description of H. pautensis it is not possible to distinguish this species from H. polyodon, also found in the río Santiago drainage according to Román-Valencia et al. (2006). Intriguing, however, the authors did not compare H. pautensis with H. polyodon in the diagnosis, but only with some of the species of the genus. Therefore, we considered H. pautensis a junior synonym of H. polyodon. Material examined. Hemibrycon polyodon, BMNH 1858.7.25.41, holotype, female, 70.4 mm SL, Guayaquil [Ecuador]. Hemibrycon coxeyi, ANSP 70155, holotype, female (x-ray), 86.0 mm SL, Hacienda Mascota, río Topo, a tributary of the río Pastaza, drainage of the río Marañon, Napo-Pastaza, Ecuador, 01º25’S 78º11’W, Apr 1931, W. J. Coxey, JC31-MRP-4. Non-type specimens. Ecuador, río Marañon drainage: KU 19978, 1, 45,7 mm SL, río Alpayacu 1 km E Mera, Pastaza, ca. 01º27’S 78º05’W, 23 Jul 1968. KU 19992, 3, 31.0-78.2 mm SL, río Negro, tributary of río Pastaza 1 km W of río Negro Twp., Tungurahua, ca. 01º24’S 78º13’W, 26 Jul 1968. KU 19995, 2, 27.7-29.3 mm SL, río Pastaza above río Negro, Tungurahua, ca. 01º24’S 78º13’W, 26 Jul 1968. KU 20004, 42 of 84 (2 c&s), 15.5-72.3 mm SL, N shore río Pastaza below río Negro (town), Tungurahua, ca. 01º24’S 78º13’W, 26 Jul 1968. Hemibrycon surinamensis Géry, 1962 Figs. 21-22 Hemibrycon surinamensis Géry, 1962: 66 (map with distribution, fig. 1), 71 (diagnosis; fig. 2 - holotype; type locality: brownscreek, km 114 of the railroad ParamariboDam, Paramaracca river basin, Surinam), 72-75 (original description), 78 (in key). Diagnosis. Hemibrycon surinamensis is distinguished from all congeners, except H. divisorensis, by the presence of a wide black asymmetrical spot covering base of caudal-fin rays and extending along entire length of caudal-fin rays 9 to 1213. Hemibrycon surinamensis differs from H. divisorensis by the absence of a black band in the lower half of the caudal A review of the Cis-Andean species of Hemibrycon 760 peduncle from the region above the last anal-fin rays to the caudal-fin base, and by the smaller number of scales along anal-fin base scale sheath (15-16 vs. 17-22). Description. Morphometric data for H. surinamensis summarized in Table 6. Largest male 80.2 mm SL, largest female 91.5 mm SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal body profile convex from nostril to dorsalfin origin, slightly concave in supraocciptal spine; posteroventrally slanted at dorsal-fin base; straight from last dorsal-fin ray to adipose-fin origin. Ventral profile of head convex. Ventral body profile slightly convex to nearly straight from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle short, nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye. Premaxilla with two tooth rows; outer row with 4-6, tricuspid teeth with central cusp slightly longer; inner row with 4 tetrato pentacuspids teeth, gradually decreasing in length from first to third teeth and last smaller; central cusp twice or three times longer and broader than other cusps. Maxilla fully toothed with 7-14 tricuspid teeth (rarely pentacuspid), except for last four or five conical teeth, with central cusp longer. Three or 4 anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 35 cusps, and 8-10 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (Fig. 22). Dorsal-fin rays ii,8 (n = 67); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin slightly concave. Adipose-fin located approximately at vertical through insertion of last three or four anal-fin ray. Anal-fin rays iii-iv,26-27 (two with 25 three with 28, mode = 27, n = 67, Fig. 2). First unbranched ray normally only apparent in cleared and stained specimens. Anal-fin profile slightly concave in females and males. Anal-fin origin posterior to vertical through base of last dorsal-fin ray. Anal-fin rays of males bearing one pair of small, elongate, retrorse bony hooks along posterolateral border of each segment of lepidotrichia, usually along last unbranched ray and twelve anterior branched rays; hooks more numerous along second through seventh branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 of each ray. Pectoral-fin rays i,10-12 (mode = 11, n = 67). Pectoral-fin tip reaching pelvic-fin origin in males but not in females. Pelvic-fin rays i,7 (one with i,8; n = 67). Pelvic-fin origin located anterior to vertical through dorsal-fin origin. Pelvic fin of males usually Fig. 21. Hemibrycon surinamensis, ZMA 100347, paratype, female, 65.0 mm SL, río Paramacca basin, Suriname. Fig. 22. Hemibrycon surinamensis, MHNG 227928, male, 58.9 mm SL. Scanning electron micrograph of right side upper and lower jaws. Scale bar = 1 mm. V. A. Bertaco & L. R. Malabarba 761 bearing 1 retrorse bony hook per segment of lepidotrichia along ventromedial border of second to ninth branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 67); lobes similar in size. Dorsal procurrent rays 10-11, and ventral procurrent rays 9-11 (n = 6). Scales cycloid, moderately large. Lateral line complete with 39-41 (mode = 41, n = 62, Fig. 3). Scale rows between dorsal-fin origin and lateral line 6-7 (mode = 7, n = 67); scale rows between lateral line and pelvic-fin origin 4-5 (mode = 5, n = 67). Predorsal scales 12-15, arranged in regular series (mode = 13). Scales rows around caudal peduncle 14. Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 12-17 scales in single series, extending to base of eighth to fourteenth branched rays. Precaudal vertebrae 16-17; caudal vertebrae 21-22; total vertebrae 38-39 (n = 10). Supraneurals 6-7 (n = 6). Gill rakers on upper limb of outer gill arch 7-9, and on lower limb 11-12 (n = 12). Color in alcohol. General ground body color yellowish. Dorsal and dorsolateral portion of head and body pigmented dark brown. One black humeral spot narrow, larger and vertically elongate, located over fifth to sixth lateral line scales and extending over 5-6 horizontal series of scales, including lateral line. Midlateral body stripe broad silvery extending from humeral region to caudal peduncle. A wide black spot covering base of caudal-fin rays and extending about median rays. Dorsal fin with dark pigmentation diffuse, and anal fin with small black chromatophores along its border forming narrow stripe in some specimens. Other fins without distinctive marks (Fig. 21). Sexual dimorphism. Males of Hemibrycon surinamensis are easily recognized by the presence of bony hooks on the dorsal-, anal-, pelvic-, and pectoral-fin rays. Males and females also slightly differ in pectoraland pelvic-fin lengths, and body depth (Table 6). Mature males with gill gland on first gill arch, covering the first branchial filaments. Distribution. Hemibrycon surinamensis is known from coastal basins of French Guiana and Suriname (Paramacca and Maroni basins), and from lower rios Tapajós, Tocantins and Xigu basins, Pará, Brazil (Fig. 4). Remarks. Géry (1962) described Hemibrycon surinamensis from the basin of Paramacca River, Suriname, based on his particular fish collection. Géry gave the catalog number of only one lot of paratypes from ZMA fish collection (ZMA 100347, paratype), and listed the remaining lots as belonging to his particular fish collection (Holotype Nr. M. 107; and 9 paratypes Nr. M. 107.2-11, except Nr. 4). Later, the holotype was donated to ZMA (catalogued as ZMA 104188), and the paratypes were distributed to MHNG and MNHN fish collections. Planquette et al. (1996) collected several specimens and lots of H. surinamensis in some river basins from French Guiana, as the Maroni, Approuague, Comté and Mana. In the 1980 decade, Michael Goulding makes several collecting expeditions in the Amazon basin, including the rio Tocantins. Most of the fishes collected by Goulding are located at MZUSP, but a large portion has not been cataloged. We have analyzed the lots of Hemibrycon collected by Goulding in 1983 in the rio Itacaiúnas, lower rio Tocantins basin and concluded that is the same species from Suriname Paratypes A B C D n Range Mean SD n Range Mean SD n Range Mean SD n Range Mean SD n Range Mean SD Standard length (mm) 7 53.3-64.8 57.5 - 65 33.5-91.5 64.7 - 20 38.6-87.1 54.3 - 5 39.5-45.6 42.7 - 7 38.9-60.2 48.1 - Percents of Standard length Predorsal distance 7 49.5-54.2 51.0 1.6 65 48.4-55.1 51.1 1.5 20 49.2-53.0 51.5 1.0 5 51.9-53.4 52.7 0.6 7 50.6-53.0 51.9 0.9 Prepelvic distance 7 42.6-47.4 44.5 1.5 65 40.9-49.2 45.4 1.6 20 41.7-47.6 45.0 1.4 5 46.0-47.1 46.5 0.4 7 43.9-47.2 46.2 1.1 Prepectoral distance 7 23.2-25.1 24.3 0.7 65 22.3-25.8 24.2 0.8 20 22.3-26.7 24.8 1.0 5 25.2-26.2 25.7 0.4 7 23.2-27.2 25.4 1.3 Preanal distance 7 59.0-65.2 61.1 2.0 65 56.9-65.1 62.0 1.7 20 57.9-63.0 60.6 1.5 5 61.6-63.5 62.4 0.7 7 60.3-62.6 61.4 0.8 Depth at dorsal-fin origin (m) 3 31.2-32.0 32.0 0.7 19 33.1-39.5 35.5 1.7 8 31.8-38.2 34.9 2.0 - - - - 2 34.5-37.5 36.0 2.1 Depth at dorsal-fin origin (f) 4 31.4-37.1 34.0 2.5 46 32.7-42.7 37.1 2.1 12 30.5-38.0 34.4 2.2 5 36.2-39.3 37.6 1.1 5 33.3-39.0 36.4 2.2 Caudal peduncle depth 7 9.7-12.8 11.1 1.0 65 10.0-12.9 11.7 0.6 20 10.0-12.0 10.8 0.6 5 11.9-12.6 12.2 0.3 7 11.6-12.7 12.2 0.3 Caudal peduncle length 7 9.1-13.9 11.9 1.5 65 7.5-14.1 12.3 1.1 20 11.7-14.5 12.7 0.8 5 11.0-12.4 11.7 0.6 7 10.5-13.0 12.0 0.8 Anal-fin base 7 30.8-33.4 32.0 0.9 65 29.7-35.9 32.4 1.3 20 29.0-35.2 32.6 1.0 5 32.4-34.1 33.2 0.7 7 30.8-35.9 33.4 1.6 Dorsal-fin length 7 24.4-27.5 25.3 1.0 65 22.0-26.7 24.6 0.9 20 21.8-25.7 23.9 1.0 5 23.9-25.5 24.8 0.6 7 25.0-25.9 25.4 0.3 Pelvic-fin length (m) 3 15.2-15.8 15.4 0.3 19 14.5-17.1 16.1 0.7 8 15.1-17.2 16.2 0.7 - - - - 2 15.7-16.5 16.1 0.6 Pelvic-fin length (f) 4 15.8-17.6 16.7 0.7 46 13.9-17.6 15.6 0.9 12 13.3-16.1 15.1 0.7 5 15.5-16.1 15.8 0.3 5 14.4-16.4 15.6 0.7 Pectoral-fin length (m) 3 20.8-22.0 21.3 0.6 19 20.4-22.9 21.7 0.8 8 20.7-23.1 22.1 0.9 - - - - 2 21.8-22.4 22.1 0.4 Pectoral-fin length (f) 4 20.7-22.9 22.2 1.0 46 19.5-24.1 21.7 1.0 12 20.7-22.3 21.3 0.5 5 21.6-22.8 22.2 0.5 5 20.6-23.6 22.6 1.2 Head length 7 22.4-25.3 24.0 1.0 65 21.1-25.7 23.1 0.8 20 21.9-25.1 23.3 1.0 5 24.4-26.2 25.0 0.7 7 22.9-25.8 24.3 1.1 Percents of Head length Snout length 7 22.9-25.1 24.2 0.8 65 21.6-27.8 23.9 1.0 20 22.2-25.2 23.6 0.9 5 23.5-25.4 24.5 0.6 7 23.0-25.8 24.9 0.9 Upper jaw length 7 45.4-48.1 46.7 1.0 65 42.7-49.8 46.7 1.5 20 43.7-49.2 47.1 1.3 5 46.0-52.4 48.5 2.5 7 45.4-49.8 48.4 1.5 Orbital diameter 7 31.9-35.6 33.9 1.2 64 30.1-37.4 33.7 1.5 20 31.1-37.9 34.7 2.3 5 30.0-34.5 32.9 1.6 7 32.5-37.2 34.3 1.9 Interorbital width 7 33.2-35.9 34.7 1.0 65 32.0-40.1 36.7 1.3 20 34.4-39.7 36.5 1.4 5 33.5-37.0 34.7 1.4 7 33.8-38.1 36.3 1.8 Table 6. Morphometric data of paratypes of Hemibrycon surinamensis (MHNG 2182.59, MNHN 1980.1435, ZMA 100.347) from Paramacca River basin, Suriname, and non-types from coastal drainages of the Guiana and Suriname (A - MHNG 1553.54-58, 2179.27, 2182.57, 2182.61-64, 2279.28, 2279.80; MNHN 1989.0046, 1994.0094, 1998.1780, 1998.1931, 2002.3511; ZMA 107.232, 107.275), from rio Tocantins basin (B - MZUSP 30529, 30530), from rio Tapajós basin (C - MNRJ 34433, 34435), and from rio Xingu basin, Brazil (D - MNRJ 34439, 34441, 34443). m, males; f, females. SD = Standard deviation. A review of the Cis-Andean species of Hemibrycon 768 edentulous portion of the maxilla smaller than toothed portion. Among stevardiine taxa larger counts are found in Cyanocharax alburnus (2-8 maxillary teeth), Mimagoniates rheocharis (3-8), Bryconamericus peruanus (3-7), B. cristiani (3-9), and B. yokiae (5-8), but only the anterior portion of maxillary is toothed in those species, leaving the edentulous portion of the maxilla clearly larger than toothed portion. Only Boehlkea shares with Hemibrycon the presence of edentulous portion of maxilla smaller than toothed portion, associated with the largest number of teeth in the maxilla. Hemibrycon differs from Boehlkea, however, in having the lobes of caudal-fin naked (vs. scaled), lateral line complete (vs. incomplete or interrupted), and larger total number of vertebrae (38-43 vs. 36). As now defined, Hemibrycon is delimited by the possession of the synapomorphies of Stevardiinae, combined with the absence of the synapomorphies diagnostic of other internal clades, as well as by the possession of an elevated number of maxillary teeth (6 to 20), leaving the edentulous portion of the maxilla smaller than toothed portion. Due to the lack of recognizable exclusive synapomorphies to the genus in the external morphology and osteology, additional characters must be included in future studies. Recently, new and inseminating genera were proposed and included in the Stevardiinae as Lophiobrycon Castro, Ribeiro, Benine & Melo (2003), Bryconadenos Weitzman, Menezes, Evers & Burns (2005), and Phallobrycon Menezes, Ferreira & Neto-Ferreira (2009). Among these, only the two last genera possess intumescent glandular tissue formed by club cells on the anterior portion of anal fin (Menezes et al., 2009), and the former have a caudal-fin organ (Glandulocaudini); all these characters are absent in Hemibrycon. The actual number of valid species of Hemibrycon still remains questionable or doubtful. Twelve species are recognized herein to the east of the Andean Cordilleras, but a revision of the species of Hemibrycon found to the west of the Andean Cordilleras is urging. Comments about the distribution of the Cis-Andean species of Hemibrycon According to Géry (1962) Hemibrycon species have a peculiar distribution in the Amazon basin, and are confined to the periphery of the basin, inhabiting the upper portions of their tributaries. They are found usually in mountain streams with clear and fast water, and do not live in the slow running rivers of the lowlands (Géry, 1962), except H. surinamensis. Hemibrycon surinamensis was originally described to Atlantic coastal rivers of Suriname and posteriorly found in coastal rivers of French Guyana (Géry et al., 1991), and according we results it also occurs in the lower rios Tapajós, Tocantins and Xingu basins, Brazil. Among Characidae genera (or Clade A genera), the peripheral distribution pattern is similar and largely congruent with the distribution given to the species of Creagrutus Günther by Harold & Vari (1994), and Vari & Harold (2001). All species of Hemibrycon from the Trans-Andean basins are different species from those in rivers east of the Andean Cordilleras, a situation found in other groups of fishes taxonomically revised, e.g., Creagrutus. Key to the Cis-Andean species of Hemibrycon 1. Humeral spot extending over 7 to 9 horizontal series of scales …………………. .…………………. .… . .…. .…. .…2 1’. Humeral spot extending over 2 to 6 horizontal series of scales …………………………………………………………3 2. 19 to 23 branched anal-fin rays; 6 to 12 scales sheath along anal-fin base; 16 to 18 predorsal scales……………H. helleri (upper río Ucayali drainage, Peru) 2’. 25 to 30 branched anal-fin rays; 13 to 28 scales sheath along anal-fin base; 12 to 16 predorsal scales……H. jelskii (upper portions of ríos Marañon, Ucayali, MadeiraMamoré drainages in Bolivia, Brazil and Peru) 3. Small humeral spot and extending over 2 to 3 horizontal series of scales; total number of pelvic fin rays 7; 3 to 4 scale rows below of the lateral line………H. mikrostiktos (upper río Ucayali drainage, Peru) 3’. Humeral spot extending over 4 to 6 horizontal series of scales; total number of pelvic fin rays 8; 4 to 9 scale rows below of the lateral line………………………………………4 4. Presence of a wide black asymmetrical spot covering base of caudal-fin rays and extending along entire length of caudal-fin rays 9 to 12-13 ………………..…………….……5 4’. Absence of a wide black asymmetrical spot covering base of caudal-fin rays……………………………………………6 5. Presence of a black band in the lower half of the caudal peduncle from the region above the last anal-fin rays to the caudal-fin base; scale sheath along anal-fin base 17 to 22; total number of gill rakers 20 to 22……………H. divisorensis (upper río Ucayali drainage, Peru) 5’. Absence of a black band in the lower half of the caudal peduncle from the region above the last anal-fin rays to the caudal-fin base; scale sheath along anal-fin base 12-17; total number of gill rakers 19 to 20………………………………………H. surinamensis (coastal basins of French Guiana and Suriname, and lower rios Tocantins, Tapajós and Xingu basins, Brazil) 6. Branched anal-fin rays 15 to 19………………………………7 6’. Branched anal-fin rays 22 to 31……………………………8 7. Lateral line scales 39; 6 scale rows above of the lateral line; 14 scales around caudal-peduncle………………H. tridens (upper río Ucayali drainage, Peru) 7’. Lateral line scales 44 to 53; 7 to 8 scale rows above of the lateral line; 16 to 18 scales around caudal-peduncle…………H. beni (río Beni drainage, Bolivia) 8. Gill rakers 16-18; scales sheath along anal-fin base 610…………………………………………………H. inambari (upper río Madre de Dios drainage, Peru) 8’. Gill rakers 19-21; scales sheath along anal-fin base 1024…………………. .…………………. .… . .…. .…. .………9 9. Lateral line scales 40 to 42 (usually 41); 7 to 8 scale rows above of the lateral line; head and body slim …………………. .…………………. .… . .…. .…. .…………10 9’. Lateral line scales 42 to 48 (usually 44-45); 8 to 10 scale rows above of the lateral line; head and body robust …………………. .…………………. .… . .…. .…. .…………11 V. A. Bertaco & L. R. Malabarba 769 10. Second tooth of premaxillary inner row teeth heptacuspidate; humeral spot extending over 5 to 6 (usually 5) horizontal series of scales………………………H. metae (río Orinoco drainage, Venezuela and Colombia) 10’. Second tooth of premaxillary inner row teeth pentacuspidate; humeral spot extending over 4 to 5 (usually 4) horizontal series of scales……………………H. taeniurus (rivers of Island Trinidad, Trinidad and Tobago) 11. Caudal peduncle scales 18 to 20; head length 22.0-26.0% of SL; upper jaw length 45.2-52.6% of HL…………H. huambonicus (río Huallaga drainage, Peru) 11’. Caudal peduncle scales 16; head length 20.9-22.9% of SL; upper jaw length 43.7-45.6% of HL………H. polyodon (río Pastaza drainage, Ecuador) Comparative material. In addition to the comparative material listed in Bertaco et al. (2007), the following specimens were analyzed: Boehlkea fredcochui, ANSP 111675, holotype, upper Amazon, Paramount Aquarium via Tropicarium Frankfurt am Main; ANSP 111668, paratype, upper Amazon from surroundings of Leticia, Colombia, Paramount Aquarium import via Herbert R. Axelrod. Bryconamericus dentatus, FMNH 56253, holotype, Piedra de Moler, upper rio Cauca basin, Colombia; CAS 39543, 4 of 5 paratypes, up river from Cartago, río Paila into río Cauca, Valle del Cauca, Colombia. Hemibrycon boquiae, FMNH 56259, holotype (x-ray), FMNH 56260, 10 (3 x-ray), upper rio Cauca basin, Boquia, Colombia; IAvH-P 7762, 29, río San Rafael, upper rio Cauca basin, Risaralda, Colombia. Hemibrycon colombianus, IAvH-P 3130, 26, río Moniquira and río Suarez, Santander, Colombia. Hemibrycon dariensis, ANSP 151226, 12, rio Tuira basin, Darién, Panama. Hemibrycon orcesi, USNM 164064, holotype, USNM 175128, paratype, río Macuma, northern tributary of upper río Morona, upper Amazon, Santiago-Zamora, Ecuador. Acknowledgements We are grateful to Scott Schaefer and Barbara Brown (AMNH), John Lundberg and Mark Sabaj (ANSP), David Catania (CAS), Mary Anne Rogers (FMNH), Andrew Bently (KU), Guy Duhamel and Patrice Pruvost (MNHN), Hernán Ortega and Max Hidalgo (MUSM), Paulo Buckup and Marcelo Britto (MNRJ), Osvaldo Oyakawa (MZUSP), Helmut Wellendorf and Ernst Mikschi (NMW), Rick Winterbotton and Erling Holm (ROM), H. Zetzsche and F. Krupp (SMF), Stanley Weitzman, Richard Vari and Sandra Raredon (USNM) for selection and loan of specimens; to Roberto Reis (MCP) and Tiago Carvalho (UL at Lafayette) by the examination of the types of H. polyodon and H. guppyi at BMNH; to Paulo Petry and Fernando Carvalho by the examination of H. helleri at MCZ; to Monica Rodrigues (LIRP) by the examination of holotype of H. dentatus; to Javier Maldonado (IAvH) by assistance in the Instituto Alexander von Humboldt; to Fernando Carvalho (UFRGS) by suggestions in the manuscript; to the Centro de Microscopia e Microanálises - CEMM, PUCRS for the SEM preparations. VAB is grateful by the Fellowships offered by the Academy of Natural Sciences, California Academy of Sciences, Field Museum of Natural History, Muséum d’historie naturelle, Geneva, National Museum of Natural History, Smithsonian Institution, and is financed by a postdoctoral fellowship from CNPq (Proc. 150042/2009-4). 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