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）作为坦巴基脂鲤（tambaqui）仔稚鱼的首个外源饵料的效果。将180尾仔鱼分配至12个水族箱中，每箱水体容积为1.5升，放养密度为每升10尾仔鱼。试验周期共计20天，受试仔稚鱼被分为3种日粮处理组：T1组（商品配合饲料）、T2组（仙女虾）、T3组（商品配合饲料+仙女虾），各组设置4个生物学重复，采用完全随机试验设计。试验期间，水体各项水质参数均维持在该物种适宜的理想范围内。接受T2组与T3组处理的坦巴基脂鲤仔稚鱼存活率分别位居前列。就仔稚鱼生长发育性能而言，仅饲喂仙女虾的试验组，其终末体重（3.48 mg）、日增重（0.14 mg·d⁻¹）及比生长速率（8.62%）均表现最优。研究同时发现，仅饲喂商品配合饲料的试验组，因存活率与生长速率偏低，其仔稚鱼发育效率较差。本研究表明，仙女虾可显著提升坦巴基脂鲤仔稚鱼的生长性能与存活率，具备作为该物种活饵料的良好应用潜力。