Caracterização da estrutura genética populacional do tubarão-crocodilo (Pseudocarcharias kamoharai) no Atlântico Equatorial utilizando marcadores moleculares.
2012; Linguagem: Inglês
ISSN
2639-6459
Autores Tópico(s)Fish Biology and Ecology Studies
ResumoFor the fishing sector, the identification and delimitation of the fishing stocks constitute fundamental information due to their direct relationship to the overall productivity and sustainable utilization of the resources. This constitutes a basic objective in terms of population management and conservation of endangered species that can be represented by the conservation of the genetic variability. Among the most exploited sharks, pelagic species have a greater complexity in terms of evaluation and monitoring due to their distributions along large geographical areas. One of these species is the crocodile shark, Pseudocarcharias kamoharai, which reaches maximum sizes of around 140 cm in total length, inhabits maximum depths of around 600 meters, and occurs in all tropical oceans including in Brazil, mainly in the Northeast region. The molecular genetic analysis using sequences of the mitochondrial DNA control region (D-loop) of 125 individuals captured in four distinct regions in the Atlantic Ocean (Western Equatorial, Northwest Africa, Gulf of Guinea and Southwest Africa), allowed the identification of 22 haplotypes which revealed a haplotype diversity of h=0627 and a nucleotide diversity of π=0.00167. These indices showed to be similar to those found in other species of pelagic sharks, also from the Atlantic sites and can be considered inside of the average levels of genetic diversity among the sharks. The value of FST=0.00125 index found in the comparisons may suggest the absence of population subdivision among the four sampled regions analyzed. Given the continued inclusion of shark species in the Red List of the International Union for Conservation of Nature and Natural Resources (IUCN), the results obtained in this study may be used to help a
Referência(s)