Revision of Prodontocharax and revalidation of Amblystilbe (Teleostei: Characidae: Cheirodontinae), with description of a new species

Abstract Prodontocharax species are revised and the genus Amblystilbe is revalidated based on analysis of type-material and additional specimens. Both genera are diagnosed based on unique synapomorphies among members of the Cheirodontinae related to shape, size, number and arrangement of teeth in the jaw bones. Prodontocharax melanotus, from the upper rio Madeira basin, Brazil and Bolivia, is redescribed, and a new species is described from the rio Huallaga basin, Peru. The genus Amblystilbe and its type-species, A. howesi, are redescribed from the Amazonas River basin, Bolivia, Brazil, and Peru, and Prodontocharax alleni is considered a junior synonym of A. howesi. The two species of Prodontocharax are distinguished by the color pattern, number of lamellae of the olfactory rosette in male and female and number of gill rakers, and differ from A. howesi by the number and shape of teeth, color pattern and number of branched anal-fin rays. According to recent studies, the species of Prodontocharax and A. howesi cluster into two distinct clades among the cheirodontines

New species of Hasemania (Characiformes: Characidae) from Central Brazil, with comments on the endemism of upper rio Tocantins basin, Goiás State

Hasemania kalunga é descrita para a bacia do alto rio Tocantins, Chapada dos Veadeiros, Goiás, Brasil. A espécie nova distingue-se das suas congêneres pelo número de escamas perfuradas da linha lateral (11-21 vs. 5-9, exceto de H. crenuchoides e H. piatan), pela presença de uma mancha umeral preta e verticalmente alongada (vs. ausência, exceto de H. crenuchoides, H. nambiquara e H. piatan), e pela ausência de escamas na base da nadadeira anal (vs. presença, exceto de H. maxillaris e H. piatan), por 19 raios principais na nadadeira caudal (vs.18 em H. piatan). Ela também difere de H. crenuchoides por dados morfométricos. A ausência de uma bainha de escamas cobrindo a base da nadadeira anal, um caráter incomum em Characidae, e o endemismo da ictiofauna do alto rio Tocantins são discutidos.Hasemania kalunga is described from the upper rio Tocantins basin, Chapada dos Veadeiros, Goiás State, Brazil. The new species is distinguished from its congeners by the number of perforated lateral line scales (11-21 vs. 5-9, except from H. crenuchoides and H. piatan), by the presence of a black vertically-elongate humeral spot (vs. absent, except from H. crenuchoides, H. nambiquara, and H. piatan), and by absence of scale sheath along anal-fin base (vs. presence, except from H. maxillaris, and H. piatan), by 19 principal caudal-fin rays (vs. 18 in H. piatan). It differs also from H. crenuchoides by morphometric data. The absence of scale sheath covering the anal-fin base, an uncommon character in Characidae, and the endemism of the ichthyofauna from the upper rio Tocantins are discussed

A new species of Boehlkea (Characiformes: Characidae: Stevardiinae) from the rio Japurá, Amazon basin, Brazil

ABSTRACT A new species of Boehlkea is described from rio Japurá, Amazon basin. The new species differs from B. fredcochui by the presence of a vertically elongate humeral spot (vs. absence), complete lateral line (vs. incomplete), four rows of scales below lateral line (vs. three), and lower number of branched anal-fin rays (17-21 vs. 22-25), and from B. orcesi by the higher number of maxillary teeth (13-14 vs. 5-12), greater head length (27.9-29.9% vs. 24.3-27.5% of SL), and by the color pattern (basal half of dorsal-fin, distal portion of pelvic-fin, lower caudal-fin lobe and anal-fin with black chromatophores vs. absence of black chromatophores in the fins)

Astyanax douradilho, a new characid fish from the rio Tramandaí system, southern Brazil (Characiformes: Characidae)

Bertaco, Vinicius A. (2014): Astyanax douradilho, a new characid fish from the rio Tramandaí system, southern Brazil (Characiformes: Characidae). Zootaxa 3794 (3): 492-500, DOI: 10.11646/zootaxa.3794.3.1

Astyanax douradilho Bertaco, 2014, new species

<i>Astyanax douradilho</i>, new species <p>(Figs. 1–2, Table 1)</p> <p> <b>Holotype.</b> MCN 19858, 1, 90.0 mm SL, Brazil, Rio Grande do Sul State, municipality of Maquiné, Barra do Ouro District, rio Maquiné basin, rio Tramadaí system, arroio Encantado, 29º36’28”S 50º12’15”W, 1 Nov 2013, V.A. Bertaco, M.A. Azevedo, C.L. Castilho & A.C. Vigo.</p> <p> <b>Paratypes.</b> Brazil, Rio Grande do Sul State, municipality of Maquiné, Barra do Ouro District, rio Maquiné basin, rio Tramadaí system. MCN 19895, 10, 51.3-72.7 mm SL, UFRGS 18390, 7, 60.5-65.5 mm SL, rio do Ouro, 29º35’12”S 50º17’00”W, 16 Dec 2010, C. Vogel, G. Rosa & L. Artioli. MCN 19896, 6, 63.7-76.0 mm SL, rio do Ouro, 29º35’12”S 50º17’00”W, 11 Jan 2011, C. Vogel, R. Paesi & G. Rosa. MCP 25371, 2, 57.1–58.3 mm SL, arroio Encantado, 29º36’28”S 50º12’15”W, 1 Sep 1999, F.G. Becker, M. Vassiliou & G. Irgang. MCP 25479, 2, 68.6–72.0 mm SL, arroio Encantado, 29º36’28”S 50º12’15”W, 31 Aug 1999, F.G. Becker, M. Vassilou & T. Finkler. MCP 25692, 1, 73.9 mm SL, arroio Lageado (Cerrito), 29º34’16”S 50º16’51”W, 4 Sep 1999, F.G. Becker, G. Irgang & M. Vassiliou. MCP 25693, 2, 59.6–67.4 mm SL, arroio Forqueta, 29º32’42”S 50º14’21”W, 23 Feb 2000, F.G. Becker, F.S. Villela, M.F. Corrêa & C.S. Villela. MCP 25698, 3, 63.7–75.2 mm SL, arroio Forqueta, 29º32’42”S 50º14’21”W, 26 Feb 2000, F.G. Becker, F.S. Villela, M.F. Corrêa & C.S. Villela. MCP 25700, 12 (3 c&s), 46.0– 70.5 mm SL, arroio Encantado, 29º36’28”S 50º12’15”W, 26 Feb 2000, F.G. Becker, F.S. Villela, M.F. Corrêa & C.S. Villela. MCP 25708, 2, 48.4–60.0 mm SL, arroio Encantado, 29º36’28”S 50º12’15”W, 22 Jan 2000, F.G. Becker, F.S. Villela, M.F. Corrêa & M.B. Fonseca.</p> <p> <b>Diagnosis.</b> <i>Astyanax douradilho</i> differs from all congeners inhabiting the rio Uruguay basin, laguna dos Patos and rio Tramandaí systems by the presence of 3–5 maxillary tricuspid teeth, except from <i>A. henseli</i> Melo & Buckup, <i>A. laticeps</i> (Cope), and <i>A. paris</i> Azpelicueta, Almirón & Casciotta, and by the absence of a conspicuous dark stripe from humeral region to caudal peduncle. Additionally, it differs from <i>A. henseli</i> by the number of gill rakers on lower branch of first arch (11–12 <i>vs</i>. 15–19), from <i>A. laticeps</i> by the number and shape of humeral spots (two vertically elongate <i>vs</i>. one oval horizontally elongate), and from <i>A. paris</i> by the number of perforated scales along the lateral line (37–39 <i>vs</i>. 34–36). The following combination of characters distinguishes <i>A. douradilho</i> from all other species of the genus: the presence of two vertically elongate humeral spots, a conspicuous caudal spot, absence of a conspicuous dark stripe from humeral region to caudal peduncle, 3–5 maxillary tricuspid teeth, 22–24 branched anal-fin rays, 3 <b>7</b> –39 perforated scales along the lateral line, head length (26.0–29.9% SL), upper jaw length (43.8–50.6% HL), and snout length (23.0–28.6% HL).</p> <p> <b>Description.</b> Morphometric data summarized in Table 1. Body compressed and elongate, with greatest body depth anterior to dorsal-fin origin. Dorsal profile of head straight or slightly convex. Dorsal body profile convex from tip of supraocciptal spine to base of last dorsal-fin ray; straight from that point to adipose fin origin. Ventral profile of body convex from mandibular symphisis to pelvic fin origin, nearly straight to anal-fin origin, and posterodorsally slanted along anal-fin base. Caudal peduncle deep, nearly straight on dorsal and ventral margins.</p> <p>Snout rounded from margin of upper lip to vertical through anterior nostrils. Head somewhat pointed anteriorly in lateral profile. Mouth terminal, jaw isognathous. Mouth slit nearly at horizontal through the middle of eye. Maxilla extending posteriorly to vertical through anterior margin of orbit reaching pupil. Maxilla widened anteroposteriorly.</p> <p>Premaxillary teeth in two rows: outer row with 4(24), 5(9), or 6*(2) tricuspid teeth, central cusp longer; inner row with five teeth, gradually decreasing in length from first to fifth; usually with four cusps on first tooth, five cusps on second to fourth teeth and three cusps on fifth tooth. Maxilla with 3(27), 4*(7), or 5(2) tricuspid teeth; central cusp broader than others. Dentary with 3(2) or 4*(28) large tri- or pentacuspid teeth, followed by six to eight small teeth, uni- to tretracuspid (Fig. 2). Median cusp in all cuspidate teeth longer than remaining cusps; cusp tips slightly curved inwardly in dentary, premaxillary teeth cusps approximately straight.</p> <p>Dorsal-fin rays i,9(1) or 10*(34); first unbranched ray approximately half length of second ray. Distal margin of dorsal fin nearly straight to somewhat convex. Dorsal fin origin slightly behind middle of SL. Origin of adipose fin at vertical through second or third last anal-fin rays. Anal-fin rays iii(20) or iv(16), 22(11), 23*(16), or 24(8). Anal fin origin posterior to vertical through base of last dorsal-fin ray. Pectoral-fin rays i,11(2), 12(14), 13*(14), or 14(6). Pectoral-fin tip not reaching pelvic-fin insertion. Pelvic-fin rays i,7*(36). Pelvic fin origin slightly anterior to vertical through dorsal-fin origin. Caudal fin forked, lobes similar in size, i,17,i*(34) principal rays. Dorsal procurrent rays 11(1), 12(1), or 13(1) and ventral procurrent rays 10(2) or 11(1).</p> <p>Lateral line complete with 37(13), 38*(18), or 39(5) scales. Scale rows between dorsal-fin origin and lateral line 6(6) or 7*(30); scale rows between lateral line and pelvic-fin origin 5*(31) or 6(5). Predorsal scales 11(9), 12*(21) or 13(4) arranged in regular series. Scale rows around caudal peduncle 14(9), 15(11), or 16*(15). Scale sheath along anal fin base 8-15 scales (32), in single series, covering base of anteriormost rays. Axillary scale, longer than wide, relatively folded in half, and extending over 1-2 longitudinal scale series.</p> <p>Precaudal vertebrae 15(1), 16(1), or 17(1); caudal vertebrae 20(2) or 21(1); total vertebrae 36(2) or 37(1). Supraneurals 5(3). Gill-rakers upper branch 6(8) or 7(6); lower branch 11(8) or 12(6); total number 17(3), 18(10), or 19(1).</p> <p> <b>Color in alcohol.</b> Dorsal and dorsolateral portions of head and body dark brown. Infraorbital and opercular areas covered with scattered, dark chromatophores. Scales on lateral body with dark brown chromatophores. Midlateral stripe very faint. Caudal spot black, triangular or irregular in shape, extending to tip of middle caudal-fin rays. Two humeral spots. Anterior one, conspicuous, vertically elongate with upper portion wider, located over third to fifth vertical series of scales, extending over 2 to 3 horizontal series of scales above lateral line; lower portion of spot narrow (1 to 2 scales pigmented), extending over 1 to 2 horizontal series of scales below lateral line. Second humeral spot large, occasionally faint, not surpassing lateral line ventrally, extending over 3 horizontal series and 2 to 3 vertical series of scales above lateral line. Scattered dark chromatophores on dorsal, adipose, caudal and anal fins. Pectoral and pelvic with few dark chromatophores. Dark pigmentation on middle caudal-fin rays and along median-distal portion of anal-fin rays (Fig. 1 a).</p> <p> <b>Color in life.</b> Color pattern similar to that described for alcohol preserved specimens. Overall and head color pattern yellowish, slightly brown. Dorsolateral portion of body dark gray. Scales on lateral body silvery. Dorsal, pectoral, and pelvic fins with anterior portion yellowish and posterior reddish. Anal fin reddish colored at distal half of first rays. Caudal fin almost completely reddish, except middle portion. Adipose fin yellowish (Fig. 1 b).</p> <p> <b>Sexual dimorphism.</b> Males with small bony hooks on dorsal-, pectoral-, pelvic- and anal-fin rays (rarely in caudal-fin). One paired bony hook per lepidotrichia in the last unbranched anal-fin ray and first to thirteenth branched anal-fin rays on median and distal portions of the rays. One paired bony hook per lepidotrichia on second to fifth branched pelvic-fin rays. Small bony hooks on distal one-third of anteriormost branched dorsal- and pectoral-fin rays, and on distal portion of middle caudal-fin rays. No other apparent sexually dimorphic features were found in the specimens examined. Gill glands (Burns & Weitzman 1996) were not found macroscopically on the first gill arch.</p> <p> <b>Distribution.</b> <i>Astyanax douradilho</i> is known from tributaries of the rio Maquiné, rio Tramandaí system, coastal drainage of Rio Grande do Sul, southern Brazil (Fig. 3).</p> <p> <b>Etymology.</b> Douradilho is a regional name for the horse color pattern consisting of a reddish brown or golden yellow. The name is an allusion to the color of the fins in live specimens. A noun in apposition.</p> <p> <b>Ecological notes.</b> <i>Astyanax douradilho</i> was collected in relatively small, clear water streams until 1 m deep, with stones and rocks on bottom, and moderate riparian vegetation. The collection localities are around 300 m above sea level. In the Encantado (Fig. 4) and Lageado streams, the pH ranged from 6.5 to 6.8, conductivity between 31.7 to 39.5 µs/cm, and oxygen level between 5.0 to 6.8 mg /l. Based on examination of several lots in fish collection, the species seems to be found only in mainstream of small rivers draining from Serra Geral formation, and was not found in the other subregion basin formed by lagoons of the Coastal Plain (Malabarba & Isaia 1992).</p>Published as part of <i>Bertaco, Vinicius A., 2014, Astyanax douradilho, a new characid fish from the rio Tramandaí system, southern Brazil (Characiformes: Characidae), pp. 492-500 in Zootaxa 3794 (3)</i> on pages 493-497, DOI: 10.11646/zootaxa.3794.3.10, <a href="http://zenodo.org/record/230065">http://zenodo.org/record/230065</a&gt