Description

SINGLE PAPER

Volume 13, Issue 2 – 8 November 2007

Wilson J. E. M. Costa: Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae), pp. 55-68

Abstract
Five new species of the genus Rivulus, subgenus Melanorivulus, are described from the middle Araguaia River basin: R. salmonicaudus n. sp., from streams and swamps directly associated with the main Araguaia River channel; R. rubromarginatus n. sp., from the Peixe River drainage; R. crixas new species, from the Crixás Açu River drainage; R. javahe n. sp., from the Verde River and Crixás Açu River drainages and, R. karaja n. sp., from the Formoso River drainage. All new species are members of the clade referred to here as the R. zygonectes species group. This group is diagnosed by the presence of a diffuse dark grey stripe between the postorbital region and caudal-fin base, in which each included species is diagnosed by the unique colour patterns on the caudal fin in males.