Journal des pêches et de l'aquaculture
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Population Genetics and Dynamics of Spotted Seatrout in the Estuarine Waters of Texas

Joel D Anderson, William J Kare

A geospatial database of spotted seatrout (Cynoscion nebulosus) abundance along the Texas shoreline was generated, using 33 years of intensive gill net sampling data by the Texas Parks and Wildlife Department. The resulting landscape demographic data was used to identify areas of low individual abundance, which were evaluated as putative subpopulation boundaries. Quantitative population genetic analysis was conducted using a recently published genetic data set of mitochondrial DNA haplotypes, and a new data set of nuclear microsatellites. A significant mtDNA AMOVA result was obtained when samples were pooled into northern, mid-coast and southern spatial partitions based upon geospatial data (Fct = 0.030, P = 0.003). This three-partition model captured more genetic divergence at the group level than any other model examined. Similarly, the three-partition model resulted in a small but significant group association in the microsatellite AMOVA (Fct = 0.003, P = 0.009). Multivariate cluster analyses of both data sets indicated that at least three distinctive subpopulations of spotted seatrout exist within Texas waters. The genetic data are consistent with previous studies that indicate the presence of distinctive subpopulations of spotted seatrout in Texas coastal waters, and with geospatial abundance data indicating areas of low abundance, between adjacent subpopulations along the northern and southern Texas coastline.