ABSTRACT Seaweeds are potential feed additives for aquaculture but their effect on fish fatty acid content and profile is largely unknown. This study was, therefore, designed to assess the effect of incorporating green macroalgae seaweed (Ulva sp.) into diets of juvenile dusky kob (Argyrosomus japonicus) on fillet fatty acid profile and concentration. Five experimental diets were formulated to contain seaweed at the following inclusion levels: 0 (Ulva0), 50 (Ulva50), 100 (Ulva100), 150 (Ulva150) and 200 (Ulva200) g/kg commercial kob feed on a dry matter basis. Seventy-seven fingerlings (9.14 ± 0.30 g) were distributed into each of 20 experimental tanks and diets were randomly allocated to tanks such that each diet had 4 replicate tanks holding 77 fingerlings. There was no dietary effect on fillet fatty acids (FA) concentrations (P > .05). The concentration of C18:3n3 (α-linolenic acid) tended to increase with Ulva inclusion levels (P > .05). However, the opposite was observed with the fillet concentrations of both C20:4n6 (arachidonic acid methyl ester) and C20:5n3 (eicosapentaenoic acid (EPA)), but the decrease was also not significant. In conclusion, while Ulva-containing diets did not enhance the FA concentration in dusky kob fillet, the values were similar to those observed in fish fed on the relatively expensive commercial kob diet.

中文翻译：

---

膳食海藻 (Ulva sp.) 不会改变南非幼鱼 (Argyrosomus japonicus, Sciaenidae) 鱼片中的脂肪酸谱和浓度

摘要 海藻是水产养殖的潜在饲料添加剂，但它们对鱼类脂肪酸含量和特征的影响在很大程度上是未知的。因此，本研究旨在评估将绿色大型海藻 (Ulva sp.) 加入幼鱼 (Argyrosomus japonicus) 日粮中对鱼片脂肪酸谱和浓度的影响。配制了五种实验日粮以含有以下含量的海藻：0 (Ulva0)、50 (Ulva50)、100 (Ulva100)、150 (Ulva150) 和 200 (Ulva200) g/kg 基于干物质的商业条饲料。77 条鱼种（9.14 ± 0.30 克）被分配到 20 个实验池中的每一个中，并且将饲料随机分配到池中，使得每个饲料有 4 个重复池，可容纳 77 条鱼种。饮食对鱼片脂肪酸 (FA) 浓度没有影响 (P > .05)。C18:3n3（α-亚麻酸）的浓度随着石莼包含水平而增加（P > .05）。然而，在 C20:4n6（花生四烯酸甲酯）和 C20:5n3（二十碳五烯酸 (EPA)）的鱼片浓度中观察到相反的情况，但降低也不显着。总而言之，虽然含石莼的饮食不会提高暗色鳕鱼片中的 FA 浓度，但其值与在以相对昂贵的商业鳕鱼饲料喂养的鱼中观察到的值相似。