Revisão taxonômica e distribuição geográfica das espécies de dekeyseria rapp py-daniel, 1985 (siluriformes: loricariidae)

Abstract

Dekeyseria Rapp Py-Daniel, 1985 comprises six species (D. amazonica, D. brachyura, D. picta, D. niveata, D. pulcher e D. scaphirhyncha) with uncertain taxonomic boundaries. Based on examination of approximately 400 specimens from different ichthyological collections and recently sampled material, all the species were reviewed taxonomically, (D expanding the characterization of three of them (D. amazonica, D. picta D. scaphirhyncha), and proposing new synonyms . brachyura and D. pulchra as synonyms of D. picta, and D. niveata as synonym of D. scaphirhyncha). Besides, two new species are preliminarily described for the genus (Dekeyseria sp. 1 and Dekeyseria sp. 2). Dekeyseria is diagnosed by head and body depressed, snout completely plated, three series of plates on the caudal peduncle and three series of lateral plates on the body with hypertrophied odontodes. The study of their characteristics resulted on the recognition of ontogenetic variation and sex dimorphism for some species. The species of the genus are usually associated to submerged logs in calm waters of streams and lakes and also boulders, although not abundant, they are widely distributed in the entire Amazon basin, including five Brazilian states, and also in the Rio Orinoco drainage, in Venezuela and Colombia.