A new long-snouted Corydoras (Siluriformes: Callichthyidae) from the rio Xingu and rio Tapajós basins, Brazilian Amazon

Abstract

Abstract A new species of Corydoras is described from the rio Xingu and rio Tapajós basins, Pará State, Brazil. The new species can be promptly distinguished from its congeners by the combination of the following features: (I) temporal sensory canal at sphenotic with two pores; (II) upper tooth plate of branchial arch with three or four series of teeth; (III) area at the corner of the mouth, ventral to the maxillary barbel, with a small, roughly triangular fleshy flap, not forming an elongated barbel-like structure; (IV) contact between posterior process of the parieto-supraoccipital and nuchal plate; (V) dark stripe transversally crossing the orbit, forming a mask-like blotch; (VI) absence of a distinct color pattern along midline of flank; (VII) dorsolateral body plates only with small, irregular, rounded or vertically elongated dark brown or black blotches; ground color of plates typically dusky but not forming large, conspicuous black patches; and (VIII) absence of a relatively large, conspicuous dark patch on anterior portion of dorsal fin.