Tuesday, August 3, 2010
Temperature Experiments on Hatchery-Cultured Red King Crabs at NOAA
NOAA researchers at the Alaska Fisheries Science Center Behavioral Ecology Laboratory in Newport, Oregon, conducted experiments to explore how temperature mediates growth and energy allocation in newly settled red king crab juveniles. Crabs used in the experiments were reared at the Alutiiq Pride Shellfish Hatchery and were shipped to Newport in May 2009. Juvenile crabs were held at four temperatures, ranging from 1.5 to 12°C, for 60 days. Temperature did not affect survival; however, growth increased exponentially with temperature. Crabs molted more frequently in warmer temperatures and had a greater increase in size with each molt. Twenty percent of the crabs held at 1.5°C never molted, while more than 90% of the crabs at 12°C molted four or more times. Biochemical analysis showed that larger crabs cultured at 12°C had higher proportions of lipids than smaller crabs cultured at colder temperatures. All crab treatments had high proportions of essential fatty acids, suggesting that rapid growth does not negatively affect condition in juvenile red king crab. Data provided by this study will help to model temperature-dependent growth and recruitment in the field, and suggest optimal temperatures for growth of juvenile king crabs intended for rehabilitation of depleted red king crab stocks. Results from this study were recently accepted for publication in the Journal of Experimental Marine Biology and Ecology, a peer reviewed scientific journal. Titled “Temperature effects on the molting, growth, and lipid composition of newly settled red king crab, Paralithodes camtschaticus,” the paper is coauthored by Allan Stoner, Michele Ottmar, and Louise Copeman. http://seagrant.uaf.edu/research/projects/initiatives/king_crab/general.