A new masked Corydoras (Siluriformes: Callichthyidae) from the Itaya and Nanay river basins, Peruvian Amazon

Abstract

Abstract A new species of Corydoras is described from the Itaya and Nanay river basins, tributaries of the Río Amazonas in Peru. The new species can be distinguished from its congeners by the following features: (I) branch of the temporal sensory canal at sphenotic, which gives rise to the supraorbital canal, with two pores, (II) upper tooth plate of branchial arch with three series of teeth, (III) area at the corner of the mouth, ventral to the maxillary barbel, with a small, triangular fleshy flap, which may variably present a small prolongation at its posterior tip, forming a short barbel-like structure, (IV) a conspicuous dark brown or black patch transversally crossing the orbit, forming a mask-like blotch, (V) absence of a distinct color pattern along midline of flank, (VI) dorsolateral body plates only with small, irregular, rounded or vertically elongated dark brown or black blotches; ground color of plates typically light yellow or beige, (VII) absence of a relatively large, conspicuous dark blotch on anterior portion of dorsal fin, and (VIII) ossified portion of hypobranchial 2 ranging from moderately developed to well developed.