Abstract

LICONA-CHAVEZ, A; CORREA-SANDOVAL, F; ROSA-VELEZ, J de la  and  CAMARENA-ROSALES, F. Genetic and morphometric analysis of Chione californiensis and C. subimbricata (Bivalvia: Veneridae) from the Mexican East Pacific and Gulf of California. Cienc. mar [online]. 2007, vol.33, n.2, pp.149-171. ISSN 0185-3880.

For the genetic and morphometric characterization of three populations of Chione californiensis and one of C. subimbricata from the Pacific Baja California and Gulf of California coastlines (Mexico), allozyme electrophoresis was performed in 23 enzymatic systems and 14 morphometric characters were analyzed. The allozymic analysis indicated a heterozygosity of more than 40% in all the populations and since some loci deviated significantly from the Hardy-Weinberg law, disequilibrium is proposed. The fixation index for the populations of C. californiensis showed little genetic structure (F_ST = 0.045, Nm = 0.363) because gene flow is limited by the location and geographic conditions of the sites from where they were collected. Nei's genetic distance grouped the two southernmost populations of C. californiensis and corroborated the systematic relationship of this species with C. subimbricata. The discriminant function analysis revealed intra- and interpopulation differences, as well as the systematic relationship between both species. Six morphometric variables were identified that contributed most to this differentiation and the Mahalanobis morphometric distances indicated differences in the morphometry of the two C. californiensis populations from the Gulf of California and the population from the Pacific. The results generated by both analyses support the inclusion of these species within the subgenus Chione proposed by Keen (1971).

Keywords : Chione; bivalves; genetics; allozymes; morphometry.

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