Abstract
Astyanax endy, new species, is described from the upper Río Bermejo basin. This species is distinguished from its congeners by the following combination of characters: markedly convex snout profile, deep body (36.6–42.2 % SL), relatively large orbital diameter (36.0–40.9 % HL), relatively short interorbital distance (31.9–37.6 % HL), deep caudal peduncle (11.7–14.1 % SL), long caudal peduncle (12.6–15.9 % SL), short upper-jaw length (34.4–40.2 % HL), maxilla scarcely reaching anterior margin of the eye, maxilla meeting mouth commissure at an oblique angle, 35–37 perforated scales in lateral line, 7/6 transverse scales, 17–24 branched anal-fin rays, tricuspidate or pentacuspidate teeth on outer premaxillary row, 1–2 tricuspidate or pentacuspidate maxillary teeth, 4 gradually decreasing dentary teeth followed by 1 intermediate and 3–6 small tricuspidate or conical teeth, and 19–21 gill-rakers in first branchial arch. A key for identification of the species of Astyanax from the Río Bermejo basin is provided.References
Almirón, A.E., Azpelicueta, M. de las M., Casciotta, J.R. & López Cazorla, A. (1997) Ichthyogeographic boundary between the Brazilian and Austral subregions in South America, Argentina. Biogeographica, 73, 23–30.
Almirón, A.E., Azpelicueta, M. de las M. & Casciotta, J.R. (2002) Astyanax ita sp. n. – a new species from the Río Iguazú basin, in Argentina (Teleostei, Characiformes, Characidae). Zoologische Abhandlungen (Dresden), 52, 3–10.
Azpelicueta, M de las M., Casciotta, J.R. & Almirón, A.E. (2002a) Two new species of the genus Astyanax (Characiformes, Characidae) from the Paraná river basin in Argentina. Revue suisse de Zoologie, 109, 243–259.
Azpelicueta, M. de las M., Casciotta, J.R. & Almirón, A.E. (2002b) Astyanax paris: A new species from the río Uruguay basin of Argentina (Characiformes, Characidae). Copeia, 2002 (4), 1052–1056.
Azpelicueta, M. de las M. & García, J.O. (2000) A new species of Astyanax (Characiformes, Characidae) from Uruguay river basin in Argentina, with remarks on hook presence in Characidae. Revue suisse de Zoologie, 107, 245–257.
Casciotta, J.R. & Almirón, A.E. (2004) Astyanax chico sp. n., a new species from the río San Francisco basin, northwest of Argentina (Teleostei: Characiformes: Characidae). Zoologische Abhandlungen (Dresden), 54, 11–17.
Casciotta, J.R., Almirón, A.E. & Azpelicueta, M. de las M. (2005) Astyanax pampa (Characiformes, Characidae), a new species from the southernmost boundary of the Brazilian subregion, Argentina. Revue suisse de Zoologie, 112 (2), 401–408.
Cope, E.D. (1894) On the fishes obtained by the Naturalist Expedition in Rio Grande do Sul. Proceedings of the American Philosophical Society, 33, 84–108.
Cuvier, G. (1819) Sur les poissons du sous-genre Hydrocyon, sur deux nouvelles espèces de Chalceus, sur trois nouvelles espèces du Serrasalmes, et sur l'Argentina glossodonta de Forskahl, qui est l'Albula gonorhynchus de Bloch. Memoirs du Museum National d'Histoire Naturelle, 5, 351–379.
Fink, W.L. & Weitzman S.H. (1974) The so-called Cheirodontin fishes of Central America with descriptions of two new species (Pisces: Characidae). Smithsonian Contributions to Zoology, 172, 1–46.
Garutti, V. & Britski, H.A. (2000) Descrição de uma espécie nova de Astyanax (Teleostei: Characidae) da bacia do alto rio Paraná e considerações sobre as demais espécies do gênero na bacia. Comunicações do Museu de Ciências e Tecnologia da PUCRS, série Zoologia, Porto Alegre, 13, 65–88.
Malabarba, L.R. (1989) Histórico sistemático e lista comentada das espécies de peixes de água doce do sistema da laguna dos Patos, Rio Grande do Sul, Brasil. Comunicações do Museu de Ciências da PUCRS, Série Zoologia, 2, 107–179.
Miquelarena, A. M. & Menni, R.C. (2005) Astyanax tumbayaensis, a new species from northwestern Argentina highlands (Characiformes: Characidae) with a key to the Argentinean species of the genus and comments on their distribution. Revue suisse de Zoologie, 112 (3), 661–676.
Miquelarena, A.M., Protogino, L.C. & López, H.L. (2005) Astyanax hermosus, a new species from the Primero River basin, Córdoba, Argentina (Characiformes, Characidae). Revue suisse de Zoologie, 112 (1), 13–20.
Taylor, W.R. & Van Dyke, G.C. (1985) Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9, 107–119.