Abstract
Kemp's ridley sea turtles, Lepidochelys kempi, underwent a population crash over a period of approximately thirty-five years that made them the most endangered of the sea turtle species. To understand the impact of the crash and to learn more about the life history of the Kemp's ridleys, DNA samples were obtained from adult female and hatchling turtles for microsatellite analysis. Average allele number and heterozygosity values were determined for four loci and compared with the values found in a healthy population of olive ridleys, L. olivacea, to determine if there was evidence of a significant loss of diversity as a result of the population crash. Differences in the mean heterozygosity and the mean number of alleles per locus were not significant (p>O. 1, p>0.25, respectively). The decline in the Kemp's ridley population does not appear to have been severe enough to affect their genetic health. Mother and offspring groups were examined at three loci for evidence of multiple paternity. In approximately 60%, three paternal alleles were detected. There was insufficient evidence to support or refute the hypothesis of mating between nesting emergences. The power of the study to detect multiple paternity was tested using simulations. Two models, in which males contributed equally or unequally to the fertilization of the eggs, were simulated. The results indicated that the study was sensitive to the model of paternity. The best fit of the data was provided by an unequal paternity model. The study, while underestimating the actual number of nests fertilized by multiple males, does support the theory of a promiscuous mating system which would help to maintain genetic diversity in a small population.
Kichler, Kristina Lynn (1996). Microsatellites and conservation genetics: genetic variability and mating behavior of the Kemp's ridley sea turtle, Lepidochelys kempi. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1996 -THESIS -K53.