title: Three new species of the killifish genusMelanorivulusfrom the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae).
abstract: Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related toMelanorivulus dapazifrom the same region, with which they share the presence of a rudimentary interarcual cartilage and a dark reddish brown distal margin on the male anal fin. The group comprisingMelanorivulus dapaziand the three new species is here named as theMelanorivulus dapazispecies group.Melanorivulus ignescenssp. n., from the upper Rio Araguaia basin, is distinguished from all other species of theMelanorivulus dapazigroup by the anal-fin colour pattern in males;Melanorivulus flavipinnissp. n.andMelanorivulus regularissp. n.from the Rio Paraguai basin are distinguished from all other congeners of theMelanorivulus dapazigroup by the colour pattern of the caudal fin and number of scales in the longitudinal series, respectively. All the new species are further unambiguously diagnosed by unique combinations of morphological characters, including meristic and morphometric data, and colour patterns. This study reinforces the importance of using live colour patterns to diagnose species and species groups of the genusMelanorivulus, but also indicates that osteological characters may be informative for species diagnosis. This study confirms the high diversity of species ofMelanorivulusin the central Brazilian Cerrado plateaus already reported in previous studies, indicating that endemic species are often restricted to short segments of a single river drainage.
authors.affiliation: Laboratory of Systematics and Evolution of Teleost Fishes, Institute of Biology, Federal University of Rio de Janeiro, Caixa Postal 68049, CEP 21941-971, Rio de Janeiro, Brazil.
authors.forename: Wilson J E M
authors.initials: WJ
authors.lastname: Costa
keywords: Biodiversity hotspot; morphology; osteology; systematics; taxonomy