A study of the population genetics of giant clams of the genus Tridacna from the Great Barrier Reef and the West Pacific. Variations in gene frequencies of allozymes and common proteins were used to estimate connectivity and dispersal between populations, and to determine the phylogeny of the genus (discrete species identities). Species studied were Hippopus hippopus, Hippopus porcellanus, Tridacna crocea, Tridacna derasa, Tridacna gigas, Tridacna maxima, Tridacna squamosa and Tridacna tevora. Not all loci were examined for all species.Allele frequencies at 6 polymorphic loci of 860 individual clams sampled from 19 populations of Tridacna maxima throughout the Pacific between November 1989 and October 1991 were examined. Collection locations were: Myrmidon, Davies, Michaelmas, Thetford, 13125, 21200, 20396 and Stapleton Reefs on the Great Barrier Reef; Marovo and Nggela in the Solomon Islands; Mili in the Marshall Islands; Bantayan and Tawi-tawi in the Philippines; Te puka in Tuvalu; Abiang and Abemana in Kiribati; Makogai and Makodragi in Fiji; and Aitutaki in the Cook Islands. Loci were: LDH-1, MDH-2, PGM-2, DIA, LGG-1, GSR.Seven polymorphic loci (GPI, MDH-1, PGM, DIAPH, AK, LGG-1, LGG-2) from 159 individuals of T. gigas were sampled from 7 populations thoughout the West Pacific (Marovo, Russell, Isabel and Nggela in the Solomon Islands; Silliman in the Philippines; Abemana in Kiribati; and Mili in the Marshall Islands) and compared to data previously obtained in 1990 from 393 individuals from 6 populations (Myrmidon, Grub, Michaelmas, Thetford, 13125 and Stapleton Reefs) from the Great Barrier Reef.28-40 individuals from 14 populations of Tridacna derasa were sampled from sites on the Great Barrier Reef (2 sites from each of Myrmidon, Bowl, 13125, 21200, 20396; and one site from Michaelmas and Escape Reefs), and from one site each in the Philippines (Scarborough Shoals) and Fiji (Makogai). Gene frequencies at 9 polymorphic loci (GPI, LDH-1, MDH-1, MDH-2, PGM, DIAPH, LGG-1, ENOL, GSR)were examined.Gene frequencies at 26 loci for 8 species of giant clam were examined. Samples were obtained between November 1989 and October 1991. Source and number of individuals sampled was: Hippopus porcellanus (Philippines, 3); Hippopus hippopus (3 -Great Barrier Reef); Tridacna squamosa (8 - GBR, Fiji, Solomon Islands); Tridacna crocea (6 - GBR, Solomon Islands); Tridacna maxima (9 - GBR, Solomon Islands, Cook Islands); Tridacna gigas (9 - GBR, Solomon Islands, Kiribati); Tridacna derasa (9 - GBR, Fiji, Palau); Tridacna tevora (1- Fiji). Polymorphic loci examined were: AAT-1, AK-1, AK-2, DIA-1, ENO-1, EST-1, GPI-1, GSR-1, IDH-1, LDH-1, LDH-2, LGG-1, LGG-2, LP-1, LP-2, LP-3, MDH-1, MDH-2, ME-1, MPI-1, NDH-1, NDH-2, PGK-1, PGM-1, PGM-2.
To estimate connectivity and dispersal between Tridacna populations, and to determine the discrete species identities.
