Genetic studies in cownose ray Rhinoptera bonasus (Chondrichthyes, Rhinopteridae) using molecular markers

Abstract

Overfishing imposes changes in life strategy of populations of organisms, especially in elasmobranchs, so that the development of research involving different biological aspects of components of this group becomes extremely important in species conservation programs. The stingray Rhinoptera bonasus is a species that has suffered increased and intense fishing pressure by being accidentally caught in trawl fisheries directed to the capture of shrimp, in which the captured fish individuals return usually dead to the sea. Rhinoptera bonasus has its occurrence identified from is distributed from Southern New England (EUA) to the South of Brazil, the available data in Brazil for this species refer more often to its anatomic studies, occurrence, distribution area and feeding habits, and less frequently to catch statistics and population structure in the areas of occurrence. In part, these difficulties stem from their morphological similarity to other species of rays that occur in sympatry (Rhinoptera brasiliensis), turning difficult the correct identification of the species at the capture. Under current conditions an assessment of their actual population status is impossible, being that the species is currently described as "near threatened" in the IUCN Red Book. Thus, aiming to provide more informations on population characteristics of R. bonasus that could result in a more efficient and sustainable management of existing stocks, the aim of this study is to present results about genomics and population genetic diversity of this stingray species in the coastal region of the Rio de Janeiro, São Paulo and Santa Catarina states, providing data about the genetic variability, structuring and gene flow among populations using molecular genetic markers in order to contribute to elasmobranch conservation studies. (AU)