EVALUACIÓN DE LA DIVERSIDAD GENÉTICA DE LA TORTUGA LORA (Lepidochelys kempii) EN TAMAULIPAS

Abstract

Kemp's ridley (Lepidochelys kempii) is the smallest of seven species of sea turtles and the only one that nests during the day massively in Mexico. The ridley population declined during the decade of the 80's from 160,000 individual to only 5000. An important characteristic of this species is its restricted geographic distribution, nesting almost only in the Mexican State of Tamaulipas more than 90% of the total world population. When a population undergoes a dramatic reduction in size or demographic bottleneck, it may also experience a genetic bottleneck, where significant losses of genetic diversity in population occur through genetic drift. Molecular biology techniques are used as a reference to assess the genetic diversity of wild populations, and these studies supported by morphological characteristics, can determine if the individuals are genetically different or grouped into the same population. In this study, I report the genetic diversity assessment of the Kemp's ridley in Tamaulipas, Mexico using microsatellite markers. It was established a successful DNA extraction method from three different types of tissue obtained from dead hatchlings along Tamaulipas coast. Only three loci out of the five used ones were successfully amplified. Markers proved to be informative (combined non-exclusion probability 0.01) with a mean of 7.5 alleles per locus. Fisher's method showed no significant differences on genotype segregation among rookeries (P>0.05). Population is in Hardy-Weinberg equilibrium. We recommend to increase number of markers to rise strengthen of the results and to provide a broader perspective. The absence of differentiation may be due to the female´s philopatry tendency, mating with males borne on different nesting sites, which would be translated on alleles shared by hatchlings even if they were born on different beaches.