Abstract

The Gulf of Mexico and Caribbean Sea are home to a variety of elasmobranch species, including five nominal species and one nominal sub-species of the triakid shark genus Mustelus (smoothhound sharks). Each of these species is listed on the IUCN’s Red List of Threatened Species; one (M. canis) is listed as Near-Threatened, three (M. norrisi, M. minicanis and M. sinusmexi-canus) are listed as Data Deficient, and one (M. higmani) is listed as Least Concern. Elucidating the spatial distribution, and population structure of these species is crucial for effective management planning and conservation of smoothound species in the Gulf of Mexico and Caribbean Sea. Thirty-two nuclear-encoded microsatellites were developed from an enriched genomic library of M. canis to test the hypothesis that there are genetically divergent stocks of M. canis throughout their range and in U.S. waters of the Gulf of Mexico and Caribbean Sea. All 32 microsatellites were tested for cross-amplification on tissue samples from individuals of M. higmani, M. norrisi, M. insularis, and M. sinusmexicanus, and assessed for differences in allele size ranges and heterogeneity of allelic richness and gene diversity. A subset of microsatellites were identified and used to develop a microsatellite panel that can be employed to distinguish among the species. The study provides information on stock structure for M. canis and a reliable genetic assay for delineation of smoothhound shark species. Results of the study can be used in management planning and conservation of smoothhound shark resources in the Gulf of Mexico and Caribbean Sea.