Arachidonic Acid in the Diet of Captive Yellowtail and Its Effects on Egg Quality

Abstract

Marine finfish require long-chain (LC) polyunsaturated fatty acids (PUFAs) for normal physiological function, and because these LC-PUFAs cannot be synthesized by the fish, they must be obtained from the diet. Three LC-PUFAs-arachidonic acid (ARA; 20:4[n-6]), eicosapentaenoic acid (EPA; 20:5[n-3]), and docosahexaenoic acid (22:6[n-3])-are especially important for growth and development of marine fish embryos and larvae. We supplemented ARA in the diet of Yellowtail Seriola dorsalis to determine whether ARA levels have an effect on egg and larval quality. Two experimental diets were offered to replicate groups of Yellowtail held in 10-m 3 tanks under ambient water temperature and photoperiod conditions. The reference diet (REF-D; 1.4 g of ARA per 100 g of total fatty acids) was a commercial premix (BioVita Starter Mash; Bio-Oregon) without ARA supplementation; the ARA diet (ARA-D; 4.7 g/100 g total fatty acids) was the commercial premix with 1.0% concentrated ARA oil (40% ARA, weight/weight) added. Fish in the REF-D treatment spawned 53 times during the spawning season for a total of 18.0 million eggs. Fish in the ARA-D treatment tanks spawned 30 times during the spawning season for a total of 13.0 million eggs. Viability, hatch rates, and egg diameter were all significantly higher in the ARA-D treatment. Fatty acid analysis of the diets showed a significant increase in ARA in the ARA-D diet, and that same increase was seen in the resulting eggs. Correspondingly, ARA-D eggs had a lower EPA : ARA ratio than REF-D eggs. The supplementation of ARA generated increases in key performance indices, which might have biological significance in a production setting. We additionally demonstrated that Yellowtail will spawn without hormone induction in small (10-m 3 ) breeding tanks, which facilitates manipulative studies of broodstock nutrition as reported here. These data represent an excellent starting point for dietary refinements in the future.

Fatty Acid Signatures in Different Tissues of Mediterranean Yellowtail, Seriola dumerili (Risso, 1810), Fed Diets Containing Different Levels of Vegetable and Fish Oils

“…Specifically, in wild and farmed Mediterranean yellowtail, the FA composition has been analysed in the muscles, liver, ovary [10,11,50,59,60], and eggs [61]. Other studies have been performed in other Seriola species, such as S. lalandi [47,62,63], S. quinqueradiata [64,65], S. dorsalis (Gill, 1863) [66,67], and S. rivoliana [45], which mainly focused on the FA composition of muscle tissues.…”

Arachidonic acid matters

“…18 Other studies revealed that higher ARA contents in gonads and eggs of wild fish compared to domesticated fish were concomitant with superior reproductive performances. 122,124,[126][127][128][129][130][131][132][133] Studies with seawater species, such as Atlantic halibut (Hippoglossus hippoglossus), 134 Japanese flounder, 135 yellowtail, 136 Guinean fingerfish (Monodactylus sebae) 137 and freshwater species, such as yellow catfish, 138 and blue gourami (Trichopodus trichopterus), 139,140 have all shown that dietary ARA supplementation positively contributed to a wide range of reproductive performance parameters, such as spawning performance, egg quality, hatching rate and larval quality, although in a certain study these parameters may not be all simultaneously affected by dietary ARA (Table 3). From these studies, the suggested optimal ARA doses in broodstock diets were varying substantially from as little as 0.6% d.w. (3.6% TFA) in Japanese flounder up to 1.6%-2.1% d.w. (13.2%-16.3% TFA) in blue gourami.…”

“…A multitude of ARA studies revealed decreased EPA deposition in fish in response to increasing dietary ARA levels. 17,20,22,73,[82][83][84]86,92,[94][95][96][97][98]104,105,[108][109][110][111][112][113][114]116,121,125,135,136,139,140,151,163,172,176,209,210 Therefore, no doubts should be present that increased dietary ARA displaces EPA retention in fish tissues.…”

The influence of dietary fish oil replacement with mixture of vegetable oils on reproductive performance, immune responses and dynamic of fatty acids during embryogenesis in Oncorhynchus mykiss

“…The gradual decrease in the concentration of LNA and increase in the concentration of ARA during embryogenesis in the present study may be linked to the bioconversion of LNA into ARA and suggesting LNA is actively transformed by elongation and desaturation mechanisms to ARA that confirmed by the findings of previous studies in O. mykiss during embryogenesis (Agh et al, ; Lazzarotto et al, ; Noori et al, ). Although several studies have demonstrated the positive influence of dietary ARA supplementation on hatching, the exact mechanism of ARA on improvement of fertilization and hatching rates of eggs was unknown yet (Henrotte et al, , ; Stuart, Johnson, Armbruster, & Drawbridge, ). It has been postulated that ARA and its cascade metabolites have the beneficial role in normal functioning of cyclooxygenase and lipoxygenase pathways during early embryo development stages (Pereira, Marques, da Conceição Baptista, Vasques, & Horta, ).…”