Twelve microsatellite loci were isolated from an enriched genomic library of the rock scallop (Spondylus calcifer). One locus was monomorphic. Overall polymorphic loci, the mean numbers of alleles per locus at one locality was 9.6 (range 3–16), and the average observed and expected heterozygosities were 0.650 and 0.707, respectively. Three loci deviated from Hardy–Weinberg equilibrium, and from these, one locus had and excess of heterozygotes and the other two loci showed deficits of heterozygotes likely due to the presence of null alleles. No evidence of linkage disequilibrium was found among loci. These loci are the first microsatellites ever reported for the monotypic family Spondylidae, and will be useful to validate the predictions of oceanographic larval transport models and connectivity between patchy reefs within fishing areas and marine reserves in the northern Gulf of California, Mexico.

Twelve microsatellite markers (six di-nucleotides, four tri-nucleotides and two tetra-nucleotides) were isolated and characterized for Callinectes bellicosus, a commercial crustacean species from the Gulf of California, Mexico. One locus was monomorphic and 11 loci were polymorphic in 32 individual samples from a single location. Overall polymorphic loci, the number of alleles per locus ranged from 2 to 24 (average 10.0), the observed heterozygosity ranged from 0.094 to 0.969 (average 0.603), and the expected heterozygosity varied from 0.089 to 0.935 (average 0.597). One locus deviated significantly from Hardy–Weinberg equilibrium due to an excess of heterozygotes, while another locus showed evidence for the presence of a null allele. No evidence of linkage disequilibrium was found among pair of loci. These markers will be helpful to estimate the level of genetic connectivity over a small spatial and temporal scale in order to identify stocks for the management of this small-scale fishery in the Gulf of California.