Astyanax endy (Characiformes: Characidae), a new fish species from the upper Río Bermejo basin, northwestern Argentina. Author J. M. Mirande Author G. Aguilera Author M. D. L. M. Azpelicueta text Zootaxa 2006 1286 57 68 http://www.zoobank.org/urn:lsid:zoobank.org:pub:89EB739D-FFDE-44FD-AD0F-9E51CC3392FD journal article z01286p057 89EB739D-FFDE-44FD-AD0F-9E51CC3392FD [[ Animalia Characiformes Characidae Astyanax genus Astyanax ]] Artificial key for identification of Animalia Characiformes Characidae Astyanax genus Astyanax species from the Río Bermejo Basin 1a. A well defined humeral spot, rounded or horizontally oval; without maxillary teeth ...... 2 1b. A vertically elongated or diffuse humeral spot; with 1-4 maxillary teeth.. ................. 3 2a. Scales in lateral line 38 to 49 (usually 44-47); usually 28-30 branched anal-fin rays... ........................................................................................................................ Animalia Characiformes Characidae Astyanax abramis species A. abramis 2b. Scales in lateral line 33 to 40 (usually 34-36); usually 23-27 branched anal-fin rays... .............................................................................................................. Animalia Characiformes Characidae Astyanax asuncionensis species A. asuncionensis 3a. Pigmentation pattern with longitudinal stripes in zigzag between rows of scales; scales with circuli on posterior field ........................................................................ Animalia Characiformes Characidae Astyanax lineatus species A. lineatus 3b. Pigmentation pattern not as above; scales without circuli on posterior field.. ............. 4 4a. Branched anal-fin rays 25 to 30 (usually 28-29); pectoral fins reaching pelvic fins, and pelvic fins reaching anal fin in mature males and females; 26-27 gill rakers on first branchial arch, outer premaxillary teeth tricuspidate ........................................ Animalia Characiformes Characidae Astyanax latens species A. latens 4b. Branched anal-fin rays 17 to 24; pelvic fins usually not reaching anal fin in mature females; 19-21 gill rakers on first branchial arch; usually with pentacuspidate teeth on outer premaxillary row .................................................................................................. 5 5a. Maxilla meeting mouth commissure at a straight angle, reaching a vertical through anterior border of eye; snout nearly straight; premaxillary and dentary teeth conspicuously expanded; 35-39 scales in lateral line ..................................................... Animalia Characiformes Characidae Astyanax chico species A. chico 5b. Maxilla meeting mouth commissure at an oblique angle, reaching the vertical through anterior border of pupil; snout markedly convex; premaxillary and dentary teeth not conspicuously expanded; 33-36 scales in lateral line .................................................. 6 6a. Pigmentation pattern reticulated, formed by finely dotted scales, especially in its posterior border; densely concentrated dark superficial chromatophores on third infraorbital, opercle, premaxilla, maxilla and dentary; hooks on all fins excepting pectorals in mature males, including 16-19 anterior anal-fin rays ........................... Animalia Characiformes Characidae Astyanax tumbayaensis species A. tumbayaensis 6b. Without reticulated pigmentation pattern; superficial chromatophores scattered only on tip of dentary, and practically absent on third infraorbital, opercle, premaxilla, and maxilla; hooks only on pelvic fins and first 12 anal-fin rays of mature males ......... Animalia Characiformes Characidae Astyanax endy species A. endy