Marine Biology

, Volume 123, Issue 4, pp 781–787

Gene flow among giant clam (Tridacna gigas) populations in Pacific does not parallel ocean circulation

  • J. A. H. Benzie
  • S. T. Williams
Article

DOI: 10.1007/BF00349121

Cite this article as:
Benzie, J.A.H. & Williams, S.T. Marine Biology (1995) 123: 781. doi:10.1007/BF00349121

Abstract

Tridacna gigas (L.) populations were sampled from 13 locations throughout the west Pacific in 1990–1991 and screened for allozyme variation at seven polymorphic loci. Significant genetic differences were found between the few large stocks of T. gigas remaining in the world. Cluster analysis identified two major regional groups of populations: a “Central Pacific” group consisting of Kiribati and the Marshall Islands, and a “West Pacific” group comprising all other populations. Within the latter group, the Great Barrier Reef populations were significantly differentiated from those in the Solomon Islands. The main routes of gene flow did not run parallel with known major surface currents as might be expected, but crossed them. Gene exchange was limited east-west between the Central and West Pacific groups and the GBR and the Solomon Islands. The lack of correspondence between the major surface currents and the routes of gene flow suggests that the genetic structure of T. gigas reflects historical patterns of migration that no longer occur, rather than presentday dispersal. These findings raise fundamental questions concerning the origin and maintenance of genetic diversity in Pacific faunas, and have important implications for the mariculture and conservation of T. gigas.

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • J. A. H. Benzie
    • 1
  • S. T. Williams
    • 1
  1. 1.Australian Institute of Marine ScienceTownsvilleAustralia