Ecological role of lipids and fatty acids in the early postembryonic development of the daubed shanny, Leptoclinus maculatus (Fries, 1838) from Kongsfjorden, West Spitsbergen in winter

Fatty acid composition of the postlarval daubed shanny (Leptoclinus maculatus) during the polar night

“…The lipid sac is a provisory organ in daubed shanny larvae, where the substantial amounts of the TAG are stored (up to 68 % dry weight), while PL, cholesterol esters and cholesterol constitute lower amounts (Falk-Petersen et al 1896;Murzina 2010;Pekkoeva et al 2017a) (Table 2). TAG in the lipid sac of the daubed shanny postlarvae at all investigated stages (i.e., L3, L4, and L4*) demonstrated the MUFA as the prevailing FA (71%-74% of the total FA in TAG) (Table 3).…”

“…The daubed shanny, Leptoclinus maculatus (Fries, 1838), is a common demersal fish in the Arctic (Makushok 1979;Meyer Ottesen et al 2014). The life history involves a pelagic juvenile stage that last from three to five years (Meyer Ottesen et al 2011), and its body (dry weight) consists of 40% lipids (Falk-Petersen et al 1986;Murzina 2010;Pekkoeva et al 2017a;Meyer Ottesen et al 2018). The abdominal part of the body of the pelagic postlarvae contains a morphophysiological structure hereafter referred to as a "lipid sac" (Falk-Petersen et al 1986;Murzina 2010), which stores lipids as triacylglycerols.…”

“…The primary function of the lipid sac in the daubed shanny is considered to be energy storage; however, lipids also contribute to buoyancy (Falk-Petersen et al 1986;Murzina 2010). The melanophores and light refraction through the lipid droplets in the pelagic larvae are believed to make them inconspicuous to predators (Falk-Petersen et al 1986;Pekkoeva et al 2017a). This provisory organ is formed in the postlarvae stage of the daubed shanny as they begin feeding.…”

Ontogenetic changes in the body structure of the Arctic fish Leptoclinus maculatus

“…The postlarvae have a unique adaptive provisory organ, the lipid sac, made up of closely packed lipid-filled compartments 4 , 5 . It is only presented in pelagic postlarvae stages with lipid content comprising up to 92% of its dry weight 6 . The lipid sac functions as an energy storage organ, possibly also providing for the buoyancy control and / or serving as a disruptive camouflage strategy.…”

“…The lipid sac of the daubed shanny postlarvae is considered to be a unique morphological trait among the Arctic marine fishes 4 . When the fish mature and settle in muddy caves at the sea floor, the lipid sac is reduced and eventually gets lost 1 , 6 , 13 . Biochemical analysis showed changes in the lipid content of the muscles and the lipid sac during the daubed shanny postlarval development 6 , 13 , whereas the detailed information about its anatomy and histology may significantly advance our understanding of structure–function features during the postlarvae ontogenetic stages.…”