A preliminary study of allozyme differences amongst Carcharhinus sharks from the continental slope near Abidjan, Côte d\'Ivoire

  • Béatrice Adepo-Gourène Université d’Abobo-Adjamé, Laboratoire de Biologie et de Physiologie Animale, UFR-SN, 02 BP 801 Abidjan 02, Côte d’Ivoire
  • Lounès Chikhi UMR CNRS 5174, Evolution et Diversité Biologique, Bât. 4R3 b2, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, cedex 4, France
  • Jean-François Agnèse IRD, Laboratoire Génome Populations Interactions et Adaptations, Université de Montpellier II, CC 63, UMR 5900, France
  • Germain Gourène Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, UFR-SGE, 02 BP 801, Abidjan 02, Côte d’Ivoire
  • Alain Hervé IRD, BP 570, Victoria, Mahé, Seychelles
Keywords: allozyme differentiation, fixed allele differences, genetic variation, sharks, species identification, West Africa

Abstract

Genetic variability of fifty-five shark specimens from the genus Carcharhinus was analysed using 18 allozyme loci. Sixteen loci were polymorphic either within, or between, species. Levels of genetic polymorphism, as measured by observed heterozygosity values, ranged from 0.008 (±0.008) to 0.056 (±0.038). Nei's (1978) genetic distances between Carcharhinus species ranged from 0.235 to 0.784. Morphological identification, using keys, classified them as members of four morphological groups, corresponding to four species: Carcharhinus signatus, C. brevipinna, C. longimanus and C. limbatus. Genetic data confirmed that the first three species were correctly identified, but that the C. limbatus individuals could be further divided into two clearly-differentiated groups, one of which is probably C. limbatus, whereas the other could either be misidentified or be a new taxon.

Keywords: allozyme differentiation, fixed allele differences, genetic variation, sharks, species identification, West Africa

African Journal of Aquatic Science 2007, 32(3): 305–310
Published
2007-11-23
Section
Articles

Journal Identifiers


eISSN: 1727-9364
print ISSN: 1608-5914