Lipids and Fatty Acids in Some Mesopelagic Fish Species: General Characteristics and Peculiarities of Adaptive Response to Deep-Water Habitat

Abstract

The lipid and fatty acid composition of muscles of mesopelagic fish species Lampanyctus macdonaldi, Bathylagus euryops, Serrivomer beanii, Scopelogadus beanii in the Irminger Sea at deep range were studied. The contents of the total lipids (TLs), total phospholipids (PLs), monoacylglycerols (MAGs), diacylglycerols (DAGs), triacylglycerols (TAGs), cholesterol (Chol), Chol esters, non-esterified fatty acids (NEFAs), and wax esters were determined by HPTLC; the PL classes were determined by HPLC; and fatty acids (FAs) were determined using GC. It was found significant differences in lipid profile of the studied fishes: Chol esters and waxes were dominant in L. macdonaldii and S. beanii, fish species with diel vertical migrations (DVM), while TAGs were prevalent in B. euryops and Sc. Beanii—non-migratory species. It was revealed the species-specific differences in FAs profiles of the studied fish. Along with this, it was detected the similarity of FAs in fish, which is associated with food sources. A comparative analysis of lipids and FAs among L. macdonaldi and S. beanii collected in the Irminger Sea and L. alatus and S. beanii collected in the Tropic Seamount revealed similar biochemical strategies for the accumulation of certain lipids characterized the mesopelagic inhabit despite latitude differences of the area of study.