Abstract:

Nine populations of giant clams, Tridacna maxima, from six islands of French Polynesia were screened for allozyme variation at ten polymorphic loci. The genetic structure of populations of T. maxima were studied at different spatial scales: within an island, between islands of the same archipelago and between archipelagos. Significant genetic differences were observed only between populations from different archipelagos, and genetic differentiation was correlated with geographical separation. However, these results were only supported by a single locus, PEP* and all other loci were homogeneous between studied populations. According to Lewontin & Krakauer's model, the genetic structure can be explained by selection. The selective factors most likely depend on the respective habitat of each archipelago. We also studied genotype-phenotype correlation using the colour of the clam mantle, and did not find any relationship between the mantle colour and the genetic structure of the individuals. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 77, 221-231.

Keywords: allozyme; coral reef; genetic variation; mollusc; peripheral populations; selection

Document Type: Research article

DOI: 10.1046/j.1095-8312.2002.00106.x

Affiliations: 1: Ecole Pratique des Hautes Etudes - ESA CNRS 8046, Université de Perpignan, 66860 Perpignan cedex, France, and Centre de Recherche et Observatoire de l'Environnement, BP. 1013, Moorea, French Polynesia