Os cascudos Aspidoras Ihering, 1907 (Siluriformes: Callichthyidae) : uma revisão taxonômica, com a descrição de uma espécie nova.

Abstract

Aspidoras was described by Ihering as a monotypic genus to harbour A. rochai. Currently, the genus comprises 24 valid species, and is relatively well distributed across the Brazilian territory, occurring from São Paulo, its southernmost record, to Ceará. After its first taxonomic review provided by Nijssen & Isbrücker 40 years ago, no extensive work aiming to elucidate the taxonomy of Aspidoras was conducted. Therefore, a comprehensive taxonomic review was carried out, allowing the clear recognition of the genus through a new diagnosis that includes a possible exclusive feature, the presence of small laminar expansions on base of the pectoral-fin branched rays. Considering the new diagnosis plus the currently available phylogenetic data, A. pauciradiatus and A. virgulatus are herein excluded from Aspidoras, being transferred to Corydoras and Scleromystax, respectively. Regarding the remaining species, some new synonymies are proposed: A. eurycephalus and A. taurus with A. albater; A. menezesi and A. spilotus with A. raimundi; and A. microgaleus and A. marianae with A. poecilus. Additionally, a new species from the rivers Araguaia and Paraguay basins in Mato Grosso State is described. The new species can be distinguished from its congeners by having the combination of two features: parapophysis of the complex vertebra well developed, and anterior portion of infraorbital 1 with poorly-developed laminar expansion, slightly surpassing posterior margin of nasal capsule. Thereby, the number of valid species within Aspidoras was reduced from 24 to 17. Redescriptions for A. albater, A. belenos, A. depinnai, A. fuscoguttatus, A. lakoi, A. maculosus, A. poecilus, A. psammatides, A. raimundi and A. velites are provided. An identification key encompassing the species of Aspidoras, with exception of A. carvalhoi, is also provided.