High level of genetic connectivity in a deep-water reef fish, Caulolatilus microps.

The life-history characteristics of blueline tilefish make them particularly vulnerable to overfishing. Although North Carolina, U.S.A. was previously considered to be the northern extent of the range of C. microps, concentrations have recently been discovered in Virginia and Maryland, with reports as far north as Montauk, New York. Attempts to manage the fishery have been hampered by a lack of information about whether the U.S. East Coast includes multiple stocks. To assess the appropriateness of alternate management options, we used 25 variable microsatellite loci and sequencing of the mitochondrial (mt)DNA control region (CR) to evaluate the genetic structure of 490 C. microps sampled from across the U.S. East Coast range. Pairwise comparisons of genetic differentiation among collection locations based on both nuclear microsatellite and mtCR sequence data were all low and non significant. No significant autocorrelation was observed across multiple distance classes, consistent with widespread dispersal., Although the assumed sedentary nature of adult C. microps suggests population structuring, the genetic data were consistent with the presence of sufficient gene flow to prevent the accumulation of significant genetic differences and supports management of C. microps as a single stock along the U.S. East Coast.