Cage culture of Etroplus suratensis (Pearlspot) was carried out in Krishnagiri reservoir, India, a highly productive reservoir to analyze the feasibility of growing this species in freshwater cages and to investigate the effect on selected environmental parameters. Fish of average weight 5.98 ± 0.52 g were stocked at 10 ind. m³ in High-Density Poly-Ethylene floating cages (3 × 3 × 2 m) made of nylon knotless net with 12 mm mesh size. Fish were fed commercial pellet feed containing 32% protein at 5–3% of body weight a day. A reference point was fixed 100 m away from the cage site to compare the water quality as well as plankton abundance with the cage site. After 7 months, the fish grew to 90.31 ± 2.48 g, with low mean weight gain during the first 2 months, and a steady increase thereafter. Overall, the growth of Etroplus in terms of the analyzed parameters viz. specific growth rate, food conversion ratio, feed efficiency ratio, and protein efficiency ratio viz. 1.3 ± 0.013, 2.87 ± 0.08, 0.35 ± 0.01 and 1.01 ± 0.03, respectively, was found to be satisfactory in freshwater cages irrespective of low survival (52%). Zooplankton and phytoplankton density at the cage was significantly higher throughout the study, maybe due to the abundance of primary nutrients from the decomposition of leftover feed.

中文翻译：

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印度热带水库中 Etroplus suratensis (Bloch, 1790) 的网箱养殖及其对水和沉积物质量的相关影响

Etroplus suratensis (Pearlspot)的网箱养殖在印度 Krishnagiri 水库进行，该水库是一个高产水库，以分析在淡水网箱中养殖该物种的可行性并研究对选定环境参数的影响。平均重量为 5.98 ± 0.52 克的鱼在 10 英寸处放养。米³在由 12 毫米网眼尺寸的尼龙无结网制成的高密度聚乙烯浮笼 (3 × 3 × 2 m) 中。鱼被喂食含有 32% 蛋白质的商业颗粒饲料，每天 5-3% 体重。在离网箱场地 100 m 处固定一个参考点，以比较网箱场地的水质和浮游生物丰度。7 个月后，鱼长到 90.31 ± 2.48 克，前 2 个月平均增重较低，此后稳步增加。总体而言，Etroplus 在分析参数方面的增长，即。比生长率、食物转化率、饲料效率比和蛋白质效率比，即。1.3 ± 0.013、2.87 ± 0.08、0.35 ± 0.01 和 1.01 ± 0.03 分别被发现在淡水网箱中令人满意，尽管存活率低（52%）。