Enrichment of Artemia nauplii with squid and catfish oil by-products enhances survival, growth, and stress resistance in Thai mahseer (Tor tambroides) larvae

AbstractThe potential of enriched live feeds, such as Artemia nauplii, to enhance the growth performance of Thai mahseer (Tor tambroides) larvae during the larviculture phase is not yet fully understood. This study evaluated the effects of Artemia enriched with squid oil (FSO) and Pangasius catfish oil (FCO) emulsions on proximate and fatty acid composition of Artemia salina nauplii and larval, larval survival, growth, , and tolerance to air exposure stress. Six enrichment treatments with varying FSO and FCO proportions were prepared: P0 (control), P1, P2, P3, P4, and P5. Feeding trials were conducted for 21 days using standardized larval densities, and fatty acid profiles were analyzed via gas chromatography. Results showed that Artemia salina nauplii enriched with P2 had the highest eicosapentaenoic acid (EPA, C20:5n-3), P1 had the highest docosahexaenoic acid (DHA, C22:6n-3), and P5 contained the highest oleic acid (C18:1n-9) and linoleic acid (C18:2n-6). Among all treatments, P1 enrichment most effectively improved larval survival, growth, and stress tolerance. Larvae fed P1 Artemia salina nauplii also exhibited higher DHA and highly unsaturated fatty acids (HUFA) levels compared to other treatments. Under these experimental conditions, P1 produced a DHA to EPA ratio of 2.89 in Artemia salina nauplii, making it the most suitable option for early feeding of Thai mahseer larvae.摘要：强化活饵料（如卤虫无节幼体（Artemia nauplii））在育苗阶段对泰国玛希尔幼鱼（Tor tambroides）生长性能的提升潜力尚未完全明晰。本研究评估了经鱿鱼油（FSO）与巴沙鱼油（FCO）乳液强化的卤虫，对卤虫无节幼体（Artemia salina nauplii）的常规营养组成与脂肪酸组成、幼体存活率、生长性能以及耐空气暴露胁迫能力的影响。本研究设置了6组不同鱿鱼油与巴沙鱼油配比的强化处理组：P0（对照组）、P1、P2、P3、P4及P5。采用标准化幼体密度开展了为期21天的投喂试验，并通过气相色谱法分析脂肪酸谱。结果显示，经P2组强化的卤虫无节幼体二十碳五烯酸（EPA, C20:5n-3）含量最高，P1组强化的幼体二十二碳六烯酸（DHA, C22:6n-3）含量最高，而P5组强化的幼体油酸（C18:1n-9）与亚油酸（C18:2n-6）含量最高。在所有处理组中，经P1组强化的饵料最显著提升了泰国玛希尔幼鱼的存活率、生长性能与胁迫耐受能力。投喂P1组强化卤虫无节幼体的试验组幼鱼，其体内二十二碳六烯酸（DHA）与高度不饱和脂肪酸（HUFA）水平也显著高于其他处理组。在本试验条件下，P1组强化的卤虫无节幼体中DHA与EPA的比值为2.89，是泰国玛希尔幼鱼早期开口投喂的最优选择。