T-115-8
Population Structure and Connectivity of Gray Triggerfish Across Its Distribution Range
Luca Antoni
,
Department of Coastal Science, The University of Southern Mississippi/Gulf Coast Research Laboratory, Ocean Springs, MS
José Castro
,
Universidad de Las Palmas de Gran Canaria
Cristiano Albuquerque
,
Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo
Agnaldo Martins
,
Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo
Roger Djiman
,
Centre de Recherches Halieutiques et Océanologiques du BENIN
Eric Saillant
,
School of Ocean Science and Technology, The University of Southern Mississippi Gulf Coast Research Laboratory, Ocean Springs, MS
The gray triggerfish, Balistes capriscus, is a reef fish exploited recreationally and commercially in various temperate and subtropical regions of the Atlantic Ocean. To date, information on population structure and connectivity among geographic stocks is lacking in this species. In this study, specimens from 13 localities across the Atlantic Ocean were assayed at 17 microsatellite loci (n=43-80 per locality) and partial sequences of the mitochondrial DNA ND4 gene (mtDNA) (n=27-39 per locality).
Analysis of both microsatellite and mtDNA datasets revealed high connectivity between the Northwest and Northeast Atlantic (FST=-0.0002, P=0.7537; ΦST=0.0017, P=0.3341) which is hypothesized to result from the pelagic transport of Sargassum-associated larvae and juveniles by the Gulf Stream. Populations from the North and South Atlantic diverged significantly in allele and haplotype frequencies (FST=0.0375, P=0.0041; ΦST=0.4776, P=0.0084), a result consistent with the reduced exchange of larvae between the two groups predicted by current patterns in the equatorial region. Finally, separate stocks were identified in Southwest Africa and Eastern Brazil during analysis of the microsatellite dataset (FST=0.0149, P<0.0001). However, differences between the two South Atlantic stocks were not significant at mtDNA sequences (ΦST=-0.0109, P=0.8997) suggesting genetic divergence between these two regional populations occurred recently.
