W. J.E.M. Costa & G. C. Brasil, 2008
A New Pelvicless Killifish Species of the Genus Rivulus, Subgenus Melanorivulus (Cyprinodontiformes: Rivulidae), from the Upper Tocantins River Basin, Central BrazilAbstract
Rivulus planaltinus, new species, from the Maranhão River drainage, upper Tocantins River basin, central Brazil, is described. It is a member of a subclade of the subgenus Melanorivulus endemic to the central Brazilian plateau, which is diagnosed by having ventral process of angulo-articular vestigial and flank intense greenish blue or greenish golden, to purplish blue above anal-fin base in males. The new species differs from all other species of the subgenus Melanorivulus by the absence or extreme reduction of pelvic fins and pelvic girdle, numerous vomerine teeth, and a wide basihyal.
Wilson J.E.M. Costa and Gilberto C. Brasil
Copeia, Volume 2008, Issue 1, pp. 82–85