Description of a new killifish of the genus Rivulus (Teleostei: Cyprinodontiformes: Rivulidae) from south eastern Peru

Abstract

Rivulus parlettei spec. nov. from south eastern Peru (Departamento Cusco) is described. It is a member of the R. limoncochae group (as diagnosed by Costa, 2010) and differs from all the other species of this assemblage by its unique colour pattern and different morphology. It is distinguished from its geographic neighbour R. christinae by irregular interrupted lines of dots wider than the interspaces on body sides (versus longitudinal rows of dots forming stripes narrower than the interspaces). The influence of the occupation of distinct microhabitats for the radiation of the clades and the possible process of speciation of the new species are briefly discussed.