A new species of hydrops (Serpentes: Colubridae: Hydropsini) from Argentina, Brazil and Paraguay

Abstract

A new species of Hydrops is described. The new species has a disjunct distribution with regard to other species in the genus, occupying subtropical to temperate areas of Parana and Plata River basins (between 19º and 28º30’S), from Pantanal in Mato Grosso do Sul, Brazil, through Paraguay and Parana Rivers, with records in the Esteros de Iberá, Argentina. It differs from all congeners in the number of total ventral scales (ventrals plus subcaudals), number of dorsal scales and color pattern. Based on our data and those of previous authors, we present the variation in lepidosis and measurements, description of the hemipenes, and known distribution for the new species. Furthermore, a key for identification of all taxa of the genus is presented.