A new Aspidoras (Siluriformes: Callichthyidae) from rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil

Abstract

During a recent ichthyological survey in Chapada Diamantina, Estado da Bahia, Brazil, a new, very distinctive Aspidoras was discovered in tributaries of the upper rio Paraguaçu. The new taxon differs from its congeners mainly in having: a poorly-developed pigmentation pattern, restricted to minute scattered blotches on dorsal region of head and body, but grouped in small, irregular blotches along the lateral body plate junction; four or five caudal vertebra, anterior to compound caudal centrum, with neural and haemal spines placed posteriorly, close to post-zygapophyses; and post-zygapophyses of the precaudal vertebrae without dorsal expansions connected with their respective neural spines. The new species shares with Aspidoras velites dorsolateral body plates not touching their counterparts dorsally, and infraorbital bones with reduced flanges that are restricted to the latero-sensory canal. Both of these are considered reductive character states, probably indicating a paedomorphic condition to both species. The new species is also compared to Aspidoras maculosus, a congener which bears the most similar color pattern and is geographically closest to the new species.