Arctic char (Salvelinus alpinus) and Rainbow Trout (Oncorhynchus mykiss) Differ in Their Growth and Lipid Metabolism in Response to Dietary Polyunsaturated Fatty Acids

1994 ◽  
Vol 51 (6) ◽  
pp. 1391-1400 ◽  
Author(s):  
Xiuwei Yang ◽  
Terry A. Dick
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Polyunsaturated Fatty Acids ◽  
Oncorhynchus Mykiss ◽  
Neutral Lipids ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Polar Lipids ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Dietary Polyunsaturated Fatty Acids

Juvenile Arctic char (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss) were fed one commercial and three casein-based diets varying in amounts of 18:2n-6 and 18:3n-3, two polyunsaturated fatty acids (PUFA), for 12 wk at 10 °C. Both species on the diet without PUFA had lower specific growth rate (SGR) but higher percentages of liver neutral lipids and 20:3n-9 in liver polar lipids than those fed high PUFA content or commercial diets. Regardless of the amount of 18:3n-3 in the diets, the percentages of 20:3n-9 and 20:3n-9/22:6n-3 in liver or muscle polar lipids were significantly lower in char than in trout; values in trout were lower than reported in other studies. These findings question the use of 20:3n-9/22:6n-3 as an indicator of essential fatty acid status for both species. Different levels of 20:3n-9, 22:6n-3, and other PUFAs in tissue polar lipids of the two species suggest that Δ6 and/or Δ5 desaturases are less efficient in char. While trout fed test diets had slightly less 20:4n-6 than wild trout, char had 1/10 less 20:4n-6 in muscle polar and total lipids than wild char, suggesting that char may require n-6 and n-3 PUFA in their diet for optimal performance.

Diurnal and nocturnal feeding activity in Arctic char (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 54 (12) ◽  
pp. 2894-2900 ◽  
Author(s):  
Anders Alanärä ◽  
Eva Brännäs
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Salvelinus Alpinus ◽  
Feeding Activity ◽  
Activity Patterns ◽  
Arctic Char ◽  
Diel Activity ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Nocturnal Feeding ◽  
Nocturnal Fish

When food is limited and competition for it is high, individual fish may adopt different diel activity patterns. We followed individual feeding activity in groups of 10 Arctic char (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss) using a combined self-feeding and PIT-tag system. Food was supplied at low and high rewards to five replicate groups of Arctic char and rainbow trout. Four categories were identified in both species: high-triggering diurnal (diurnal fish with the highest self-feeding activity), low-triggering diurnal, nocturnal, and nontriggering fish. On average, the photophase proportion of the total daily activity was approx 90% in diurnal and approx 20% in nocturnal individuals. Rainbow trout offered high rewards did not show any diel preferences. Diurnal Arctic char and rainbow trout with the highest self-feeding activity were initially larger and had the highest growth rates, indicating a high social position. Nocturnal fish were initially smaller and their proportion of trigger actuations much lower than the high-triggering diurnal fish. These still grew successfully whereas nontriggering fish grew significantly less. Thus, some individuals with a low social status may apply an alternative strategy to attain adequate growth by feeding at night when dominant individuals are less aggressive. This may be referred to as concurrent dualism (diurnalism and nocturnalism).

Effects of polyunsaturated fatty acids and some of their metabolites on mitotic activity of vascular smooth muscle explants from the coronary artery of rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 75 (1) ◽  
pp. 80-86 ◽  
Author(s):  
B. Gong ◽  
R. Townley ◽  
A. P. Farrell
Keyword(s):  
Fatty Acids ◽  
Smooth Muscle ◽  
Rainbow Trout ◽  
Coronary Artery ◽  
Vascular Smooth Muscle ◽  
Polyunsaturated Fatty Acids ◽  
Oncorhynchus Mykiss ◽  
Thymidine Incorporation ◽  
Mitogenic Effect ◽  
Rainbow Trout Oncorhynchus Mykiss

This study is the first to examine the effects of polyunsaturated fatty acids and some of their metabolites on [3H]thymidine incorporation into vascular smooth muscle explants from the coronary artery of rainbow trout (Oncorhynchus mykiss). At a concentration of 120 μM, eicosapentaenoic acid (EPA; 20:5ω3), arachidonic acid (AA; 20:4ω6), and eicosatrienoic acid (ETA; 20:3ω6) all approximately doubled [3H]thymidine incorporation relative to controls. At a concentration of 20 μM, EPA had no significant effect, while ETA inhibited and AA caused an almost 5-fold increase in [3H]thymidine incorporation. The large mitogenic effect of 20 μM AA was completely inhibited by simultaneous addition of EPA to the culture medium. ETA only partially inhibited the mitogenic effect of 20 μM AA. Four AA-derived eicosanoids (or their stable analogues) were also tested. [3H]Thymidine incorporation was at least doubled with 1000 ng/mL carbacyclin (a prostacyclin analogue), 120 ng/mL prostaglandin F2α, and U-46619 (a thromboxane A2 analogue), but did not reach the level of stimulation produced by 20 μM AA. Leukotriene C4 had no significant effect. We conclude that dietary modulation of polyunsaturated fatty acids (PUFAs) in salmonids could have significant effects on coronary vascular smooth muscle mitosis through the incorporation of PUFAs into cell membranes and the production of eicosanoids.

scholarly journals Apparent Digestibility of Macronutrients and Fatty Acids from Microalgae (Schizochytrium sp.) Fed to Rainbow Trout (Oncorhynchus mykiss): A Potential Candidate for Fish Oil Substitution

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 456
Author(s):  
Amélie Bélanger ◽  
Pallab K. Sarker ◽  
Dominique P. Bureau ◽  
Yvan Chouinard ◽  
Grant W. Vandenberg
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Oil ◽  
Nutrient Digestibility ◽  
Fish Feed ◽  
Potential Candidate ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aquaculture Feed

Aquaculture feed formulation has recently turned its focus to reduce the reliance on marine-derived resources and utilise alternative feedstuffs, as an approach to improve the environmental sustainability of the aquaculture sector. The fish oil market is highly volatile, and availability of this commodity is continuously decreasing for use in aquaculture. Currently, a growing number of commercial efforts producing microalgae are providing omega 3-rich oil for sustainable aquaculture feed. This study was focused to determine the nutrient digestibility of a marine microalga, Schizochytrium spp., which is rich in docosahexaenoic acid (DHA) and long-chain polyunsaturated fatty acids (LC-PUFA), as a novel dietary lipid source that could be utilized effectively by rainbow trout (Oncorhynchus mykiss). A whole-cell Schizochytrium spp. biomass was used in the digestibility experiment at two different temperatures, 8 °C and 15 °C. No significant differences were detected between the two temperatures for the apparent digestibility coefficients (ADCs) of the dry matter (94.3 ± 4.9%), total lipids (85.8 ± 0.0%), crude proteins (89.5 ± 1.8%), energy (83.1 ± 1.7%) and fatty acids (85.8 ± 7.5%). The ADCs of the nutrients, energy, DHA and other fatty acids showed that Schizochytrium spp. is a high-quality candidate for fish oil substitution and supplement of LC-PUFA in fish feed with vegetable oils.

Trophic ecology of nonanadromous rainbow trout in a post-glacial lake system: partial convergence of adfluvial and fluvial forms

2018 ◽  
Vol 96 (8) ◽  
pp. 818-827 ◽  
Author(s):  
M.C. Arostegui ◽  
T.P. Quinn
Keyword(s):  
Rainbow Trout ◽  
Life Histories ◽  
Sockeye Salmon ◽  
Trophic Ecology ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Dolly Varden ◽  
Isotopic Signatures ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Dolly Varden Salvelinus Malma

The rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) is one of many salmonid species exhibiting a gradient of life histories including fluvial (stream-resident), anadromous (ocean-migrant), and adfluvial (lake-migrant) forms, the last of which is less extensively studied than the other two. Our goal was to determine the extent of diet segregation between fluvial and adfluvial rainbow trout. We collected stomach content and stable isotope data on rainbow trout sampled in stream and lake habitats in a southwestern Alaska watershed during summer and compared them with data on sympatric stream- and lake-specialist char species, Dolly Varden (Salvelinus malma (Walbaum in Artedi, 1792)) and Arctic char (Salvelinus alpinus (Linnaeus, 1758)), respectively. Rainbow trout in streams fed largely on aquatic insects, while those in the lake ate primarily benthic snails and amphipods. The trophic segregation of stream-resident and lake-migrant rainbow trout mirrored but was less extreme than the divergence of lotic Dolly Varden and lentic Arctic char in the same system. Spawning sockeye salmon (Oncorhynchus nerka (Walbaum in Artedi, 1792)) provided a nutrient subsidy in the form of eggs that supported rainbow trout in both stream and lake (littoral) habitats, causing their isotopic signatures to converge. This study augments knowledge of partial migration and trophic divergence within populations.

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