Tiny but Fatty: Lipids and Fatty Acids in the Daubed Shanny (Leptoclinus Maculatus), a Small Fish in Svalbard Waters.

Svetlana A Murzina,Jorgen Berge,Svetlana N Pekkoeva,Nina N Nemova,Ekaterina A Kondakova,Kseniia A Filippova,Alexei M Orlov,Stig Falk-Petersen,Zinaida A Nefedova

doi:10.3390/biom10030368

Abstract

The seasonal dynamic of lipids and their fatty acid constituents in the lipid sac and muscles of pelagic postlarval Leptoclinus maculatus, an ecologically important fish species in the Arctic food nets, in Kongsfjord, Svalbard waters was studied. The determination of the qualitative and quantitative content of the total lipids (TLs), total phospholipids (PLs), triacylglycerols (TAGs), cholesterol (Chol), cholesterol esters (Chol esters) and wax esters was analyzed by TLC, the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and sphingomyelin (SM) were determined by HPLC, and fatty acids of total lipids using GC. The lipid sac is a system of cavities filled with lipids, and it is not directly connected to organs of the digestive system. The wall’s inner layer is a multinuclear symplast that has a trophic function. The results provide additional knowledge on the role of lipids in the biochemical and physiological adaptation of fish to specific environments and clarify the relationship between fatty acids and the food specialization of postlarvae. Analysis of the fatty acid (FA) profile of TLs in the muscles and lipid sac of daubed shanny pelagic postlarvae showed it to be tissue- and organ-specific, and tightly associated with seasonal variations of environmental factors (temperature conditions and trophic resources).

Highlights

Lipids are one of the diverse, multifunctional, and basic groups of biochemical molecules
The histomorphological study of the lipid sac (LS) of postlarval L. maculatus confirmed that the LS is a complex of lipid-filled compartments that is not directly connected to the digestive system (Figures 3–5)
This paper presents results on the seasonal dynamics of lipids and their fatty acid (FA) components in the muscles and the lipid sac of postlarval L. maculatus inhabiting Kongsfjord in the summer, winter, and spring in the Arctic, with particular attention paid to the role of lipids in the adaptation of young fish to seasonal variations in temperature and photoperiods, as well as an important biotic factors associated with the number, species composition, and availability of food objects

Summary

Introduction

Lipids are one of the diverse, multifunctional, and basic groups of biochemical molecules. Individual lipid classes in the body, those of fish, perform several functions, each of which is crucial in specific ecological and physiological conditions [7]. Fatty acids (FAs), which are mainly in a bound state in the body, are the most mobile components of lipid molecules and are characterized by multifunctionality [8]. Fatty acid constituents of lipids are incorporated into adaptive reactions relatively quickly, and under both normal and stress-induced conditions, various FAs provide the body with the choice of alternative ways (mechanisms) of response: regulation of the physical–chemical state of biomembranes, changes in enzyme activity without changing protein concentration, and the synthesis of biologically active mediators [9]. A major proportion of the fish lipid FA complexes are long-chain and highly unsaturated FAs, which emphasizes their important functional role in the body [8]. Arctic marine organisms, including fish, accumulate high amounts of monounsaturated long-chain FAs (such as C20 and C22) that, together with polyunsaturated FAs (PUFAs), have significant biological effects on organisms, including humans

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