Features in the Lipid Status of Two Generations of Fingerlings (0+) of Atlantic Salmon (Salmo salar L.) Inhabiting the Arenga River (Kola Peninsula)

Abstract

The present research focused on determining the lipid status of salmon fingerlings (0+) in early development after dispersal form groups of spawning nests in biotopes of different hydrological conditions. The revealed qualitative and quantitative differences in the levels of phospholipids and fatty acids among two generations of Atlantic salmon fingerlings (0+) living in different biotopes of the Arenga River (a tributary of the Varzuga River) may be associated with the peculiarities of their genetically determined processes of the biosynthesis and modification of individual lipid classes and trophoecological factors (food spectrum, quality and availability of food objects, and hydrological regime). The research was organized to observe the dynamics of these developmental changes from ages 0+ to 2+.

Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River

“…Freshwater fish, compared with marine food-derived 18:3ω-3, more actively convert this molecule to long-chain PUFAs [ 2 , 20 ]. The 22:6ω-3/18:3ω-3 ratio, indicating the level of ω-3 PUFA metabolism, increased from 0.6 to 1.1 with age in the studied fish, suggesting that the increased amount of long-chain PUFAs in the juveniles at age 1+ might be associated with the start of fatty acid profile modification from a freshwater type to a marine type, consistent with the results of a previous study in fish aged 2+ and smolts (3+), inhabiting another biotopes of the Varzuga River [ 12 , 13 , 14 ]. Changes in the FA spectrum reflecting increasing PUFAs promote smoltification and the further migration of smolts to the sea [ 21 ].…”

“…The SFA/PUFA ratio decreased in salmon juveniles (from 0.98—fish at age 1+ to 0.78—fish at age 2+), reflecting increased levels of ω-3 PUFAs. We detected the same dynamic in a previous study on salmon juveniles (0 +, 1+, 2+, and 3+ smolts) from other biotopes of the Varzuga River (the Arenga tributary and the littoral of the Varzuga River) [ 14 ].…”

“…Comparing the level of TLs and their certain lipid classes in young Atlantic salmon inhabiting the Sobachji shoal of Varzuga River showed that the fingerlings had a higher lipid status in which the PLs and TAGs concentrations were high. Previous analogous studies in October 2009 examining the lipid status of fingerlings after hatching showed active resettling in another biotope, the Arenga shoal of the Varzuga River [ 12 , 13 , 14 ]. We compared the lipid status of the fingerlings from the Sobachji and Arenga shoals and observed that the fingerlings inhabiting the Arenga shoal had lower TL levels, reflecting low TAGs and EfCHOLs storage and lower length–weight characteristics.…”

“…It was shown that foraging conditions are more favorable for young age groups (0+) of salmon in small tributaries of the Varzuga River comparing to the mainstream [ 17 ]. The quantitative level of TAGs in fish, including fatty Salmonids, shows food supply and energetic reserve accumulation, which are important for further overwintering in the Arctic Rivers, such as the Varzuga River [ 13 , 14 , 18 ], while the qualitative profile of TAGs is tightly associated with the species composition of food objects. These storage lipids also play important roles in the adaptive reactions of organisms associated with membrane lipid modifications [ 1 ].…”

Dietary effect of varying linseed oil compositions on growth response, survival and polyunsaturated fatty acid levels in Tilapia (Oreochromis niloticus)

“…In this study, tilapia were raised under same exogenous conditions therefore culturing period and diet were the possible factors that could affect fatty acid profile of fish under study. From our findings, DHA, total n3 and n3/n6 ratio increased significantly (P<0.05) from month 1 to month 3 in both tissues (Table 6 and 7), an observation which relates with previous finding that fatty acid profile in fish is dependent on fish age (Parlov et al, 2009, Nemova et al, 2015aNemova et al, 2015b;Denis and Nina, 2016). A study on Atlantic salmon indicated that in two year feeding period, the levels of n3 fatty acids increased from 24 to 29.5%, DHA increased from 5.4 to 8.6% and n3/n6 ratio increased from 2.5 to 3 (Svetlana et al, 2003).…”