Undergraduate researcher compares growth of juvenile red and blue king crabs

Two-year-old juvenile blue (left) and red (right) king crabs reared under identical conditions. Photo by Ben Daly.

Jaspri Sylvan completed her freshman year at Brown University and returned to her hometown to assist Miranda Westphal, fisheries graduate student at the University of Alaska Fairbanks, Juneau Center. Sylvan hopes to learn how growth patterns vary in juvenile blue and red king crabs. This is of interest because red king crabs have moved into areas previously occupied by blue king crabs in the Pribilof Islands, and interactions between the two species may limit recovery of blue king crabs.

Crabs were cultured at the Alutiiq Pride Shellfish Hatchery in 2008 and 2009 and shipped to Juneau as recently settled instars. Westphal reared both species individually under identical laboratory conditions and photographed each molt, and Sylvan is analyzing the blue king crab photos. Results suggest that juvenile red king crabs are much larger than blue king crabs of the same age—two-year-old juvenile red king crabs are about 49 mm carapace width, while blue king crabs are about 18 mm carapace width. Thus, blue king crabs of the same age might be vulnerable to red king crab predation.

Sylvan has been involved with AKCRRAB research for the past three years. Her plans include attending graduate school and conducting research in Alaska. Future AKCRRAB studies will examine interactions between red and blue king crabs, which may be important to population recovery and potential restoration efforts.

News Flash is edited by Ben Daly. AKCRRAB is a research and rehabilitation project sponsored by the Alaska Sea Grant College Program, UAF School of Fisheries and Ocean Sciences, NOAA Fisheries, the Alutiiq Pride Shellfish Hatchery, community groups, and industry members. For more information go to http://seagrant.uaf.edu/research/projects/initiatives/king_crab/general.