Population genetic structure of the crashed snook fishery (Centropomus spp.)

Snook (Centropomus spp.) are an important game fish in the warmer coastal regions of the West Atlantic and East Pacific Oceans. In Texas, the snook fishery crashed >80 years ago and has exhibited weak signs of recovery. Here, we investigated the patterns of population genetic structure of snook in Texas with 16S mtDNA and 9 microsatellite markers. Three species of snook were identified: C. undecimalis, C. poeyi, and C. parallelus. The mtDNA of Texan C. parallelus form a monophyletic lineage that is 0.8% divergent from C. parallelus in Florida and Costa Rica. Centropomus poeyi and C. parallelus exhibited a pattern consistent with rampant hybridization and introgression and were so intertwined that we analyzed them as a single stock. Both C. undecimalis and C. poeyi - C. parallelus exhibited elevated homozygosity consistent with inbreeding. Mild chaotic genetic patchiness in C. undecimalis and C. poeyi - C. parallelus was mostly explained by elevated levels of kinship that are also associated with inbreeding. There was one instance where a sample of juveniles shared higher kinship coefficients with adults from another location than each other, suggesting that the juveniles originated near the sample of adults, in Texas. Overall, these results suggest that the recovery of the Texas snook populations has been slow due to low amounts of migration from other locations in the Gulf of Mexico.Life SciencesCollege of Science and Engineerin