Conservation Genetics

, Volume 11, Issue 4, pp 1587–1591 | Cite as

Evidence of olive ridley mitochondrial genome introgression into loggerhead turtle rookeries of Sergipe, Brazil

  • Estéfane Cardinot Reis
  • L. S. Soares
  • G. Lôbo-Hajdu
Short Communication


The coastline of Sergipe state hosts the main Brazilian nesting sites of Lepidochelys olivacea (Eschscholtz, 1829). The second most abundant species of turtles in Sergipe is Caretta caretta (Linnaeus, 1758). Both sea turtle species, respectively known as olive ridley and loggerhead, are currently listed as endangered by the International Union for the Conservation of Nature and Natural Resources. The genetic diversity of the Sergipe loggerhead population (N = 51) was assayed by analyzing 627 bp from the control region of mitochondrial DNA in nesting females. Three haplotypes were identified: CC-A4, CC-A24 and CC × LO. The last one was recorded for specimens considered hybrids because they represent L. olivacea’s mtDNA, but had the external morphology of C. caretta or of a mixture of both species. Based on the two types of hybrids, it was hypothesized that at least two hybridization events had occurred: a more ancient hybridization event, accompanied by introgression (F2 or later backcrosses), and a recent one (F1), both of which involving the same L. olivacea haplotype. The incidence of L. olivacea mitochondrial genome introgression into the C. caretta rookeries was only observed in Sergipe, which could be related to the large numbers of L. olivacea in this region and an overlap of reproduction periods and distribution areas of both species. This may also be associated to global warming since it might alter the sex ratio of sea turtles, thus facilitating interspecific mating. Awareness of gene flow between these species will significantly influence the development and implementation of adequate management strategies.


Sea turtles Hybridization mtDNA control region Genetic diversity Conservation strategies 



We are grateful to CENPES/PETROBRAS (Centro de Pesquisas da PETROBRAS) for supporting the “Mamíferos e Quelônios Marinhos” project, which included this study. The Projeto TAMAR-ICMBio staff collected the samples and provided the necessary field assistance. We acknowledge CAPES, PROCIÊNCIA-SR2-UERJ, FAPERJ and CNPq/MCT for fellowships and grants. The present study followed all ethical guidelines and legal requirements of Brazil for sampling an endangered species.


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Estéfane Cardinot Reis
    • 1
  • L. S. Soares
    • 2
  • G. Lôbo-Hajdu
    • 1
  1. 1.Instituto de Biologia Roberto Alcântara Gomes, Departamento de Genética, Laboratório de Genética Marinha (LGMar)Universidade do Estado do Rio de Janeiro (UERJ)Maracanã, Rio de JaneiroBrazil
  2. 2.Fundação Centro Brasileiro de Proteção e Pesquisa das Tartarugas MarinhasProjeto TAMAR-ICMBioRio Vermelho, SalvadorBrazil

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