Essential fatty acid requirement of juvenile red drum (Sciaenops ocellatus)

Abstract

Feeding experiments and laboratory analyses were conducted to establish the essential fatty acid (EFA) requirement of red drum (Sciaenops ocellatus). Juvenile red drum were maintained in aquaria containing brackish water (5 ± 2‰ total dissolved solids) for two 6-week experiments. Semipurified diets contained a total of 70% lipid consisting of different combinations of tristearin [predominantly 18:0] and the following fatty acid ethyl esters: oleate, linoleate, linolenate, and a mixture of highly unsaturated fatty acids (HUFA) containing approximately 60% eicosapentaenoate plus docosahexaenoate. EFA-deficient diets (containing only tristearin or oleate) rapidly reduced fish growth and feed efficiency, and increased mortality. Fin erosion and a "shock syndrome" also occurred in association with EFA deficiency. Of the diets containing fatty acid ethyl esters, those with 0.5-1% (n-3) HUFA (0.3-0.6% eicosapentaenoate plus docosahexaenoate) promoted the best growth, survival, and feed efficiency; however, the control diet containing 7% menhaden fish oil provided the best performance. Excess (n-3) HUFA suppressed fish weight gain; suppression became evident at 1.5% (n-3) HUFA, and was pronounced at 2.5%. Fatty acid compositions of whole-body, muscle and liver tissues from red drum fed the various diets generally reflected dietary fatty acids, but modifications of these patterns also were evident. Levels of saturated fatty acids appeared to be regulated independent of diet. In fish fed EFA-deficient diets (containing only tristearin or oleate), monoenes increased and (n-3) HUFA were preferentially conserved in polar lipid fractions. Eicosatrienoic acid [20:3(n-9)] was not elevated in EFA-deficient red drum, apparently due to their limited ability to transform fatty acids. Red drum exhibited some limited ability to elongate and desaturate linoleic acid [18:2(n-6)] and linolenic acid [18:3(n-3)]; however, metabolism of 18:3(n-3) did not generally result in increased tissue levels of (n-3) HUFA. Based on these responses, the red drum required approximately 0.5% (n-3) HUFA in the diet (approximately 7% of dietary lipid) for proper growth and health.

Effects of dietary lipid and environmental salinity on growth, body composition, and cold tolerance of juvenile red drum (Sciaenops ocellatus)

“…The red drum muscle was extracted with 5 volumes of a hexane: ethanol mixture (4:1 v/v) to reduce endogenous lipid levels; the muscle provided approximately 0.35% (n-3) HUFA when added to the diet at 20.7% (dry). Therefore, the diets other than those containing untreated menhaden oil were marginally adequate in EFA (Lochmann and Gatlin 1993). Dietary lipid and dextrin levels were adjusted to provide 3.60 kcal available energy/g (Serrano et al 1992).…”

“…A significant (p < 0.05) main effect and no interaction allowed data to be pooled prior to mean separation by Duncan's multiple range test; whereas, a significant main effect and interaction precluded pooling of data; 4 muscle weight x 100/total weight; 5 liver weight x 100/total weight; 6 IPF weight x 100/total weight. were determined as described by Lochmann and Gatlin (1993). These measurements also were subjected to factorial ANOVA and Duncan's multiple range test.…”

“…Significant effects of dietary lipid on weight gain and feed efficiency were observed, although all the diets marginally met the requirement of red drum for EFA, which has been estimated to be 0.3 to 0.6% (n-3) HUFA in the diet or approximately 7.0% of total dietary lipid (Lochmann and Gatlin 1993). In the present study, the red drum muscle contributed approximately 0.35% (n -3) HUFA in the diet, or 5.0% of total lipid.…”

Fatty acid and proximate composition of wild male and female king angelfish (Holacanthus passer) gonads during the ripe and spent developmental stages

“…The remaining lipid extracted after the CF determination was used for fatty acid analysis. Fatty acids were transesterified with boron trifluoride and fatty acid methyl esters (FAME) were analyzed with a Varian 3800 gas chromatograph equipped with a 30 m × 0.25 mm fused silica capillary column and a flame ionization detector as previously described (Lochmann and Gatlin, 1993). Fatty acids were identified by comparison of retention times to those of known standards, and quantified by using an internal standard (heptadecanoic acid, 17:0); they were expressed as mg g -1 of gonad wet weight.…”

Fatty Acid Contents of Lyophilized and Frozen Portunus sanguinolentus Crab Meat

“…The effects of different types of lipids on growth and tissue fatty acid composition have been investigation for a number of cultures species (Lochmann and Gatlin III, 1993;Fair et al, 1993;Nematipour et al, 1992). In the past decades, studies on crustacean fatty acids have focused on the nutritional requirements of brooders during ovarian development (Teshima et al, 1983) or juvenile growth (Xu et al, 1994;Wen et al, 2003).…”