Two new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin, Brazil

Abstract

Two new species of Corydoras are described from the rio Madeira basin, Brazil. The intermediate long-snouted new species can be distinguished from its congeners by presenting the following combination of features: posterior margin of dorsalfin spine with laminar serrations directed towards the origin of the spine; presence of two longitudinal black stripes on flanks; anterior portion of dorsal fin with sparse black chromatophores, not forming any conspicuous pattern; absence of a conspicuous black marbled coloration pattern on head; black spots on caudal fin, some spots arranged, forming transversal bars; and brownish dorsal-fin spine. The short-snouted new species can be distinguished from its congeners by the following combination of features: short mesethmoid; posterior laminar expansion of infraorbital 2 very reduced, not in contact with compound pterotic; two or three longitudinal black stripes on flanks; absence of an oblique or vertical black blotch across the eye; anterior portion of dorsal fin with sparse black chromatophores, not forming any conspicuous pattern; and ventral surface of trunk naked or covered by sparse platelets.Duas espécies novas de Corydoras são descritas da bacia do rio Madeira, Brasil. A espécie nova de focinho longo intermediário pode ser distinguida de suas congêneres por apresentar a seguinte combinação de características: margem posterior do espinho da nadadeira dorsal com serrilhas laminares direcionadas para origem do espinho; presença de duas faixas pretas longitudinais nos flancos; porção anterior da nadadeira dorsal com cromatóforos pretos esparsos, sem formar nenhum padrão conspícuo; ausência de um padrão de coloração marmoreado de preto conspícuo na cabeça; manchas pretas na nadadeira caudal, algumas delas alinhadas, formando barras transversais; e espinho dorsal amarronzado. A espécie nova de focinho curto pode ser distinguida de suas congêneres por apresentar a seguinte combinação de características: mesetmóide curto; expansão laminar posterior do infraorbital 2 muito reduzida, sem contato com o pterótico composto; duas ou três faixas pretas longitudinais nos flancos; ausência de uma mancha preta oblíqua ou vertical através do olho; porção anterior da nadadeira dorsal com cromatóforos pretos esparsos, sem formar nenhum padrão conspícuo; e superfície ventral do tronco nua ou coberta por plaquetas esparsas.

Redescription of Corydoras undulatus Regan, 1912 (Siluriformes: Callichthyidae), with comments on the identity of Corydoras latus Pearson, 1924

“…2c), 4 ([26]: 291, fig. 4) and 5 (Fig 5B), whereas the typical pectoral-fin spine serration pattern of the lineage 8 species is characterized by the presence of moderately-developed laminar serrations, mostly directed towards origin of spine ([19]: e150063, fig. 3c), and which can be used to distinguish the species within this lineage from all others congeners.…”

“…Vertebral counts include only free vertebrae, with the compound caudal centra (preural 1+ ural 1) counted as a single element. The stripes were counted as in Tencatt & Ohara [19]. …”

Fishes from the Jaru Biological Reserve, Machado River drainage, Madeira River basin, Rondônia State, northern Brazil

“…The current work contributed 24 species to the general inventory of the Machado River and 26 species to the inventory conducted in Conservation Units in the Rondônia State. Additionally, the material deposited in the Brazilian collections enabled the accomplishment of recent taxonomic studies, which contributed to enhancing the knowledge of the ichthyofauna of both the Madeira River (Rocha et al 2008a, Rocha et al 2008b, Zanata & Ohara 2009, Ribeiro et al 2011, Ohara 2012, Marinho & Ohara 2013, Zanata & Ohara 2015, Ohara & Lima 2015a, Tencatt & Ohara 2016a, Ohara & Neuhaus 2016, Pastana & Ohara 2016, and the Machado River (Ohara & Lima 2015b, Ohara & Marinho 2016.…”

A new species of Aphanotorulus (Siluriformes: Loricariidae) from the rio Aripuanã basin, Brazil

“…The rio Aripuanã basin hosts a considerable diversity of fishes, with 26 new species described in the past two decades (Kullander, 1995;Ribeiro et al, 2011, Deprá et al, 2014Zawadzki, Holanda Carvalho, 2014;Tencatt, Ohara, 2016), which indicates the need for strong conservation measures. However, the rio Aripuanã basin is one of the several rivers in the Amazon basin targeted for construction of hydroelectric dams.…”