A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio São Francisco basin, Brazil

Abstract

A new species of Corydoras is described from the rio São Francisco basin in northeastern Brazil, Minas Gerais and Bahia States. The new species is distinguished from most of its congeners by the anterior portion of the infraorbital 1 very large, conspicuously expanded towards the anteroventral margin of the snout and almost entirely covering its lateral margin. Other characters that distinguish the new species are the infraorbital 2 slender on its dorsal tip, contacting only sphenotic and not compound pterotic; and the presence of two laterosensory canals on trunk. A phylogenetic analysis including the new species found it sister-group of C. flaveolus, and both species sister-group of C. paleatus. An identification key to the species of the rio São Francisco basin is also provided.Uma espécie nova de Corydoras é descrita da bacia do rio São Francisco no nordeste do Brasil, estados de Minas Gerais e Bahia. A espécie nova se distingue da maioria de suas congêneres por apresentar a porção anterior do infraorbital 1 muito desenvolvida, expandindo-se conspicuamente em direção à margem anteroventral do focinho, quase cobrindo completamente sua margem lateral. Outros caracteres que distinguem a espécie nova são o infraorbital 2 estreito em sua extremidade dorsal, em contato apenas com o esfenótico e não com o pterótico composto, e presença de somente dois canais látero-sensoriais no tronco. Uma análise filogenética incluindo a espécie nova encontrou-a como grupo-irmão de C. flaveolus, e ambas como grupo-irmão de C. paleatus. Uma chave para identificação das espécies da bacia do rio São Francisco também é fornecida.

A new long-finned Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the lower rio Paraná basin, Brazil

“…Corydoras gryphus has this bone generally almost reduced to a canal whereas the remaining species have a relatively thicker (Fig. 2b) or very thick (see Tencatt et al, 2013: fig. 2c) infraorbital 2 bone due to the more developed posterior laminar expansions.…”

A new species of Aspidoras (Siluriformes: Callichthyidae) from a small coastal drainage in northeastern Brazil

“…According to the most recent phylogenetic studies (Alexandrou et al, 2011;Vera-Alcaraz, 2013), Aspidoras is paraphyletic since A. pauciradiatus and A. virgulatus are members of other clades. Despite that, A. kiriri can be unequivocally assigned to Aspidoras by having all the synapomorphies presented by Britto (2003) and a general morphological pattern very similar to A. rochai, type species of the genus, contrary to A. pauciradiatus and A. virgulatus, which are morphologically compatible with the species of lineages 4/5 and 3 sensu Alexandrou et al (2011), respectively.…”

“…Morphometric and meristic data follow Reis (1997), with modifications of Tencatt et al (2013). Measurements were obtained using digital caliper to the nearest 0.1 mm.…”

“…Osteological terminology follows Reis (1998), except for parieto-supraoccipital instead of supraoccipital (Arratia, Gayet, 1995), compound pterotic instead of pteroticsupracleithrum (Aquino, Schaefer, 2002), and scapulocoracoid instead of coracoid (Lundberg, 1970). The suprapreopercle sensu Huysentruyt, Adriaens (2005) is treated here as a part of the hyomandibula according to Vera-Alcaraz (2013). Vertebral counts follow Britto et al (2009).…”

New species of Scleromystax Günther, 1864 (Siluriformes: Callichthyidae) - extending the meridional distribution of genera endemic to the Atlantic Forest

“…In those Corydoras, the expansion fully contacts the compound pterotic, while the contact is limited to the sphenotic in the new taxon. Interestingly, the infraorbital series seems to be a useful source of taxonomic features for Corydoradinae (Tencatt et al, 2013).…”