Phylogenetic relationships in rays ( Dasyatis , Elasmobranchii) from Ceará State, Brazil

Abstract

Stingrays of the genus Dasyatis can be found in all tropical seas, and are considered as the most exploited fishing resources among the elasmobranchs. The goal of this study was to identify the phylogenetic relationships among four Dasyatis species (D. americana, D. guttata, D. centroura e D. marianae), which stand out in the small-scale fisheries of Ceará State, Brazil. Tissue samples were collected from those four species and from the guitar fish, Rhinobatos percellens, to be used as the outgroup in this analysis. The genetic distance was determined by PCR-RAPD markers. Six primers were analysed. Genetic distances determined relationships between the species. A most parsimonious tree was obtained, in which three monophyletic groups were found. The phylogenetic relationships were established between the four Dasyatis species. D. guttata was the most distant species from the other three. The genotype distance found between D. americana and D. centrou a was the shorter one, and the new species D. marianae was found to be closer to the group composed by those two species. The fact of elasmobranchs being ecologically and socio-economically important implies that the knowledge produced in this phylogenetic study is a relevant contribution to guide decision-makers in the searching for sustainable exploitation of these resources.