The effect of fairy shrimp “branchoneta” (Dendrocephalus brasiliensis) as the initial diet of tambaqui postlarvae

ABSTRACT. The effect of fairy shrimp “branchoneta” as the first exogenous feed for tambaqui postlarvae was evaluated. A hundred and eighty larvae were distributed in 12 aquariums, containing 1.5L of water and the stocking density was 10 larvae per liter. The trials lasted for 20 days and postlarvae were submitted to three diets (T1: Commercial feed, T2: branchoneta, and T3: Commercial feed with branchoneta), with a completely randomized design with four replicates for each treatment. During the trials, the water quality parameters were kept within ideal conditions for the species. The tambaqui postlarvae submitted to T2 and T3 showed better survival rates respectively. Regarding the postlarval development, larvae fed with only branchoneta had a better final weight (3.48 mg), daily weight gain (0.14 mg day-1), and the best specific growth rate (8.62%). The results also showed that the tambaqui postlarvae fed with only commercial feed developed less efficiently due to lower rates of survival and growth. The present study indicates that the branchoneta promoted greater development and survival rates of the tambaqui postlarvae and therefore, it presents good potential as a live food for the species.摘要：本研究评估了仙女虾“branchoneta”作为坦巴奎鱼（tambaqui）仔稚鱼初始外源饲料的饲喂效果。试验将180尾仔稚鱼均分至12个水族箱中，每箱水体容积为1.5升，放养密度为10尾/升。试验周期为20天，设置三组饲料处理方案：T1组为商品配合饲料，T2组为branchoneta，T3组为商品配合饲料与branchoneta混合投喂，采用完全随机设计，每组设置4个重复。试验期间，水体各项水质参数均维持在该物种适宜生长的理想范围内。投喂T2与T3饲料的坦巴奎鱼仔稚鱼存活率分别更高。就仔稚鱼生长发育而言，仅投喂branchoneta的仔稚鱼最终体重（3.48mg）、日均增重（0.14mg·d⁻¹）以及特定生长率（8.62%）均为最优。研究结果同时显示，仅投喂商品配合饲料的坦巴奎鱼仔稚鱼，因存活率与生长速率较低，其生长发育效率更差。本研究表明，branchoneta可有效提升坦巴奎鱼仔稚鱼的生长发育水平与存活率，因此其作为该物种的鲜活饲料具备良好应用潜力。