Combination of diet and water salinity in larviculture of piabanha-do-Pardo ( Brycon vonoi , Lima 2017)

ABSTRACT Two experiments were carried out to study piabanha-do-Pardo (Brycon vonoi) larvae development. In the first, six different diets were evaluated, being Artemia sp., plankton, feeds, feeds + Artemia sp., feeds + plankton, and Prochilodus hartii (curimba) larvae. In the second, four different water salinity levels (0, 2, 4, and 6‰) were tested. Both assays were entirely randomized design experiments, lasting for 10 days. At the end of these trials, fish biomass, survival, total length, weight, and specific growth rate were measured. Additionally, water quality, temperature, oxygen, pH, and electric conductivity measurements were made every three days. The curimba larvae diet presented higher survival rate (47.2%) and biomass weight (2.5 g) than the other diets, which were similar among each other. Piabanha-do-Pardo larvae weight, length, and specific growth rate varied with the offered diets. All water salinity treatments showed better results than those observed for fresh water. When cultivated in 2‰ salinization, larvae had 52.5% survival rates and 0.49 g biomass weight, while in the fresh water these results were 6.6% and 0.23 g, respectively. To conclude, we may identify curimba larvae as an adequate diet, and a 2‰ water salinity as recommended if Artemia sp. larvae are fed to piabanha-do-Pardo larvae.

摘要 本研究开展两项实验，以探究帕尔多河脂鲤（piabanha-do-Pardo，Brycon vonoi）的幼体发育规律。第一项实验评估了6种不同饵料，分别为卤虫属（Artemia sp.）、浮游生物、配合饲料、配合饲料与卤虫属组合、配合饲料与浮游生物组合，以及哈氏原唇齿脂鲤（Prochilodus hartii，curimba）幼体。第二项实验测试了4种不同水体盐度梯度（0、2、4和6‰）。两项实验均采用完全随机设计，试验周期均为10天。试验结束后，测定了鱼体生物量、存活率、总体长、体重及比生长速率。此外，每3天测定一次水质指标，包括水温、溶解氧、pH值与电导率。投喂哈氏原唇齿脂鲤幼体的实验组，其存活率（47.2%）与鱼体生物量（2.5 g）均显著高于其余各组，其余各组间无显著差异。不同饵料对帕尔多河脂鲤幼体的体重、体长及比生长速率均有显著影响。所有盐度处理组的试验结果均优于淡水组。当水体盐度为2‰时，幼体存活率达52.5%，生物量为0.49 g；而淡水组的对应指标仅为6.6%与0.23 g。综上可知，投喂哈氏原唇齿脂鲤幼体是适配帕尔多河脂鲤幼体的优质饵料；若投喂卤虫属幼体，则推荐将水体盐度设置为2‰。