Fatty Acid Profiles in the Gonads of Red King Crab (Paralithodes camtschaticus) from the Barents Sea

Abstract

Red king crab (Paralithodes camtschaticus) is a large shelf species native to the Pacific Ocean. Due to its high commercial value, this species was introduced into the Barents Sea, where it has formed a new population that now supports a stable commercial fishery. Information on fatty acid profiles in different tissues of the Barents Sea P. camtschaticus is scarce. For this reason, the gonads of red king crabs collected at a coastal site in the Barents Sea during the summer were analyzed for fatty acid composition by gas-liquid chromatography. The proportions of total saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids in the ovaries of P. camtschaticus were 25.9 ± 2.0%, 22.5 ± 2.3%, and 51.6 ± 2.5%, respectively; in the testes, these levels accounted for 35.1 ± 5.7%, 19.1 ± 2.0%, and 45.8 ± 4.5%, respectively. Fatty acid profiles were similar in larger and smaller red king crabs and crabs with old and new shells. Concentrations of fatty acids were higher in ovaries compared to testes, reflecting higher reproductive efforts in female red king crabs. High levels of docosahexaenoic and eicosapentaenoic fatty acids detected in the ovaries of red king crabs from the Barents Sea indicate that these gonads can be a good alternative source for these fatty acids in the human diet and/or for extracting important fatty acids for use in the medical and pharmaceutical industries.

Nutritional Quality and Fatty Acids Composition of Invasive Chinese Mitten Crab from Odra Estuary (Baltic Basin)

“…The differences in the fatty acid content among individuals of different sizes may be attributed not only to size but also to the maturity stage of the gonads and the physiological state [ 50 ]. For example, Dvoretsky et al [ 51 ] reported that the size of female red king crabs ( Paralithodes camtschaticus ) did not affect the fatty acid content in their edible parts, which is consistent with the findings of Ying et al [ 42 ] on Chinese mitten crabs. When evaluating the ratio of PUFA to SFA fatty acids, it was found that the most favorable ratio in nutritional terms characterized gonadal lipids: 1.74 and 1.64 (small and large females, respectively), while the least favorable ratio was for hepatopancreas lipids, which, depending on sex and size, was between 0.91 and 1.19.…”

“…These values are considerably lower compared to various species of marine crabs. For example, according to Dvoretsky et al [ 51 ], the n-3 to n-6 PUFA ratio in the gonads of red king crabs from the Barents Sea exceeds 4. When comparing these values to Chinese aquaculture crabs, the ratio ranged from 0.5 in crabs fed with frozen waste to 1.1 in those fed with formulated feed [ 54 ].…”

“…In Chinese natural waters, the ratio varied from 0.54 to 1.7 depending on the maturity stage of the gonads [ 42 ]. It is worth noting that the n-3 PUFA content and the n-3/n-6 value in Chinese mitten crabs are lower compared to other crab species [ 51 ].…”

Fatty Acids in the Eggs of Red King Crabs from the Barents Sea

“…Pearson correlation coefficients were calculated for log-transformed data to identify potential associations between fatty acid content in the eggs and ovaries of red king crabs. Ovary fatty acid content data for the same females used in the egg fatty acid analysis were extracted from our previous publication [19]. Statistical analyses were carried out using NCSS PASS 2004 and PAST 3.26.…”

“…Important by-products, such as the hepatopancreas [15] and shell [16], are used for the production of chitin, chitosan, α-glucosidase inhibitors, and the anticancer agent prodigiosin, as well as proteolytic enzymes and non-protein components such as essential fatty acids [17]. Recently, the fatty acid composition of other by-products, such as hemolymph and heart muscles, which are currently discarded at sea after standard onboard processing, has also been investigated [18,19].…”