Marine Biology

, Volume 132, Issue 4, pp 547–557

Genetic evidence for inter-oceanic subdivision of bigeye tuna (Thunnus obesus) populations

  • J. R. Alvarado Bremer
  • B. Stequert
  • N. W. Robertson
  • B. Ely
Article

DOI: 10.1007/s002270050420

Cite this article as:
Alvarado Bremer, J., Stequert, B., Robertson, N. et al. Marine Biology (1998) 132: 547. doi:10.1007/s002270050420

Abstract

Bigeye tuna (Thunnus obesus Lowe, 1839) are a commercially important species of tuna found in the Atlantic, Indian, and Pacific oceans. To initiate an analysis of bigeye tuna population-structure, three PCR–RFLP assays were developed based on the published mtDNA control-region sequences of four bigeye tuna. Population analyses using these three restriction assays on a total of 248 individuals resulted in an array of 13 composite haplotypes. A total of 347 nucleotides of mtDNA control-region sequence was characterized for 11 of the 13 composite haplotypes. Phylogenetic analyses demonstrated that the DNA sequences belong to two monophyletic clades. However, only one of the three restriction assays was able to discriminate between the two clades. The other two assays were confounded by excessive homoplasy. Both parallel (independent occurrences of the same nucleotide change) and convergent (different nucleotide changes within the same restriction site) changes of restriction sites were observed. These results emphasize the importance of DNA sequence-analysis for the interpretation of restriction-site polymorphism data. Analyses of the frequency distribution indicated that samples of bigeye tuna from the Atlantic Ocean were genetically distinct from those found in the Indian and Pacific oceans. Thus, these results reject the null hypothesis of a single global population of bigeye tuna.

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • J. R. Alvarado Bremer
    • 1
  • B. Stequert
    • 2
  • N. W. Robertson
    • 1
  • B. Ely
    • 1
  1. 1.FISHTEC Genetics Laboratory, Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Fax: +803 777 4002 e-mail: jaimeab@biol.sc.eduUS
  2. 2.ORSTOM Centre de Recherches Océanologiques, P.O. Box V18, Abidjan, Ivory Coast, AfricaCI

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