LARDY, C.H.*; PARR, L.A.; San Jose State Univ.; San Jose State Univ.: Clinal and Biogeographical Genetic Variation of the Dungeness Crab (Cancer magister): Implications for Marine Reserve Design

The Dungeness crab (Cancer magister) is a large crustacean that is found along the western coast of North America, from Alaska to Baja California. This species has high conservation value for many people, due to its importance in both the commercial and sport fishing industries. The goal of this study is to ascertain the mitochondrial genetic variability among adult Dungeness crabs in California, in order to more closely examine the dispersal capabilities of the species at the southernmost end of its range. Our hypothesis is that, due to extensive mixing during the larval stage, adult crabs will be genetically homogenous throughout California. To test our hypothesis, a ~415 base pair region of the Cytochrome c Oxidase subunit I (COI) mitochondrial gene was isolated and sequenced from 216 adult crabs from Crescent City to Port San Luis, California January-June 2005. Sequences were compared within and between populations in California. In addition, sequences were compared to 701 COI sequences collected in the past (1997-2004) from adult, juvenile, and larval Dungeness crabs from parts of Alaska, Oregon, and Washington, in order to gain a more complete picture of Dungeness crab population structure throughout its range. Three common haplotypes were found among all locations, with slight clinal variation from the northernmost end of the species� range down through California. Results support our hypothesis, with genetic diversity indicating a high dispersal capability among Dungeness crabs, allowing them to retain high amounts of gene flow between populations. Understanding the dispersal capabilities of the species will aid in the effective design of marine reserves and management of the Dungeness crab fisheries along the species� range.