Fatty acids in the circulatory system of an invasive king crab from the Barents Sea

Abstract

We assayed fatty acids in the cardiac muscle and hemolymph of adult crabs collected in the coastal Barents Sea. Polyunsaturated fatty acids were the major fatty acids (273 μg mL–1 or 42.8% in the hemolymph and 3130 μg g–1 or 59.7% in the cardiac muscle) followed by saturated fatty acids (201 μg mL–1 or 33.9% and 1290 μg g–1 or 24.8%, respectively) and monounsaturated fatty acids (143 μg mL–1 or 23.3% and 815 μg g–1 or 15.6%, respectively). The n-3/n-6 ratios in these tissues were 3.4 and 4.3, respectively. Fatty acid profiles were similar in females and males, in crabs with different shell conditions and in different-sized crabs. The crabs captured on soft bottoms contained significantly higher concentrations of fatty acids in their hemolymph than the crabs from hard bottoms probably owing to differences in their diets. In general, fatty acid levels in the cardiac muscle were 1.5–3 times higher than in the leg muscle reflecting higher functional load of the heart compared to walking legs. We suggest that both byproducts that now are discarded during red king crab processing could be considered additional sources for extracting valuable n-3 fatty acids.