Abstract

The gray triggerfish (Balistes capriscus) is a reef fish that occurs along the Western Atlantic coast from Nova Scotia to Argentina. In the United States the species is exploited mostly by recreational fisheries in the northern Gulf of Mexico and South Atlantic regions. Recent stock assessments indicated that the species is being overfished and a rebuilding plan is in progress. The fishery is currently managed as a single stock for the southeast United States region in the absence of reliable information on stock structure. We developed a sequencing assay for a 617 base pairs fragment of the ND4 gene encoded by mitochondrial DNA. Thirty samples from South Texas (off Port Isabel) and 29 from South-East Florida (off Jupiter) were assayed and the data used to conduct a preliminary assessment of genetic variation and stock structure of gray triggerfish in the southeast United States. Results revealed that the gene surveyed was variable in the species with 14 and 17 haplotypes found in the South Texas and South- East Florida samples respectively. Analysis of molecular variance did not indicate significant genetic heterogeneity between the two geographic populations. Inference power in the study was reduced due to the small sample sizes and the use of only one genetic locus. Because of these limitations, subtle genetic differences, as is commonly observed in marine fishes, may not be revealed by the present dataset. Further study employing larger sample sizes, additional locality samples and additional loci including hypervariable-nuclear-encoded microsatellites is warranted and in progress.

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