Rivulus Poey

Wilson J. E. M. Costa, 2004, Rivulus uakti sp. n. and R. amanapira sp. n. (Teleostei: Cyprinodontiformes: Rivulidae): two new species from the upper Rio Negro, Brazilian Amazon., Zootaxa 465, pp. 1-12 : 2

[[ Rivulus Poey ]]

Rivulus Poey is the most speciose and geographically widespread genus of the Rivulidae, comprising about 100 valid species (Costa, 2003a, b, c; Costa, in press) occurring between southeastern Mexico (about 20° N) and northeastern Argentina (about 30° S). Some species groups have been suggested based upon apomorphic morphological features (Costa, 1991, 1995a, 1998, 2003c). One of these groups is an Amazonian clade diagnosed by a unique arrangement of frontal scales and the presence of an oblique infraorbital dark gray bar through chin, conditions not occurring in other rivulids (Costa, 2003c). It includes R. atratus Garman , R. ornatus Garman , R. rectocaudatus Fels and de Rham , R. romeri Costa , and R. tecminae Thomerson, Nico and Taphorn , and is herein termed Rivulus atratus species group . Two new species of this group, collected in the upper Rio Negro basin, northern Brazil, are herein described.