Genetic Variation of Gray Triggerfish in U.S. Waters of the Gulf of Mexico and Western Atlantic Ocean as Inferred from Mitochondrial DNA Sequences

Abstract

Gray triggerfish Balistes capriscus is a reef fish exploited by recreational and commercial fisheries in the southeastern United States. Recent stock assessments indicated that the species is overfished, and a rebuilding plan is in progress. The U.S. fishery is currently managed as a single stock owing to the absence of reliable information on stock structure. We sequenced a 617‐base‐pair fragment of the ND4 mitochondrial gene in a total of 150 specimens from five localities (South Texas, Louisiana, West Florida, southeastern Florida, and South Carolina) encompassing the exploited range of the species in the USA. Analysis of molecular variance, spatial analysis of molecular variance, and spatial autocorrelation analysis did not reveal significant spatial heterogeneity in haplotype distributions within the studied range. Significant departure from neutrality was inferred from neutrality tests and may reflect the signature of a rapid population expansion following the recent glacial epochs, an inference that was supported by the results of Bayesian coalescent analysis. While the present results are consistent with management of the species as a single stock, development of additional genetic markers is needed to increase the resolution in genetic analyses and evaluate fine‐scale genetic stock structure in the region.Received January 10, 2011; accepted May 5, 2011

Phylogeography, Population Structure, and Historical Demography of Black Drum in North America

“…Bayesian skyline plots should be interpreted cautiously because the inferred expansion times are strongly influenced by substitution rates used in the analysis (Ho et al 2008;Grant 2015) as well as by sample size, sampling scheme, and natural selection (Grant 2015). However, our estimates of expansion times for the Black Drum are similar to those inferred for other species that inhabit the western Atlantic Ocean and Gulf of Mexico, such as 25,000 years ago for the Silky Shark Carcharhinus falciformis (Domingues et al 2018), 10,000-20,000 years ago for the Southern Flounder Paralichthys lethostigma (Anderson et al 2012), and 10,000-67,000 years ago for the Gray Triggerfish Balistes capriscus (Antoni et al 2011). An alternative explanation for the phylogeographic pattern that we observed in Black Drum is that the divergence between the two haplogroups originated as a result of isolation by distance due to post-Pleistocene expansion from one region to the other.…”

“…2012), and 10,000–67,000 years ago for the Gray Triggerfish Balistes capriscus (Antoni et al. 2011). An alternative explanation for the phylogeographic pattern that we observed in Black Drum is that the divergence between the two haplogroups originated as a result of isolation by distance due to post‐Pleistocene expansion from one region to the other.…”

“…Mismatch distributions, Fu's F S , and Bayesian skyline plots support the hypothesis that Black Drum underwent either late-or post-Pleistocene demographic and range expansion. Postglacial expansions have been reported or inferred for a number of other marine organisms that occur in the Gulf of Mexico and western Atlantic Ocean, including decapod crustaceans (McMillen-Jackson and Bert 2003), sharks (Escatel-Luna et al 2015Domingues et al 2018), and teleost fishes (Williams et al 2008;Antoni et al 2011;Anderson et al 2012). Estuarinedependent organisms of the Gulf of Mexico and northwestern Atlantic Ocean benefitted from the warming climate that occurred after the termination of the Last Glacial Maximum (19,000 years ago; Clark et al 2009).…”

Spatial connectivity in an adult‐sedentary reef fish with extended pelagic larval phase

“…The lack of divergence among regional samples is consistent with a preliminary assessment based on mitochondrial DNA conducted by Antoni, Emerick, and Saillant (). Genetic discontinuities within the sampled area have been evidenced in a variety of other marine and coastal species, in particular between the Gulf of Mexico and the U.S. east coast (Avise, ), or between populations east and west of Mobile Bay (Karlsson, Saillant, & Gold, ; Portnoy & Gold, ).…”

Development and characterization of microsatellite markers in the gray triggerfish (Balistes capriscus)

“…The species is receiving increasing management in the United States due to overexploitation by fisheries (Valle et al 2001). To date, information on population structure in gray triggerfish is limited to a study of variation at the mitochondrial DNA ND4 gene (Antoni et al 2011). In order to further investigate population genetics in this species, hypervariable microsatellite markers were isolated from enriched genomic libraries.…”