ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, 700 120, India.
ICAR-Central Institute of Fisheries Education, Yari Road, Versova, Mumbai, 400 061, India.
Sci Rep. 2022 Jun 14;12(1):9869. doi: 10.1038/s41598-022-13570-x.
The present study was conducted for 240 days to evaluate the effects of stocking density based on growth attributes, digestive enzymes, muscular composition, biochemical and physiological responses of Labeo rohita fingerlings in tropical inland open water cages. L. rohita (30.35 ± 1.08 g) were randomly distributed into three treatments, namely low stocking density, LSD (10 m), medium stocking density, MSD (20 m) and high stocking density, HSD (30 m) in triplicates. Fish were fed twice daily with CIFRI CAGEGROW® floating feed (crude protein-28%, crude fat-4%). Fish growth and feed efficiency were higher (p < 0.05) in LSD, however, MSD registered a higher yield. Amylase and protease activity reduced whereas lipase activity increased with increasing stocking density. Muscle crude protein and crude fat formed an inverse correlation. The fillet quality deteriorated at higher stocking densities based on Muscle pH, drip loss and frozen leakage rate. The stress biomarkers level (glucose, cortisol, superoxide dismutase and catalase) increased in serum under crowding conditions. Glutamate oxaloacetate transaminase and glutamate pyruvate transaminase in serum were significantly increased in HSD. Serum protein levels decreased with the increase in stocking densities. Body ionic imbalance (Na, Cl and K) was observed under crowding stress. Based on growth attributes and multiple biomarker responses, L. rohita @ 10 m was found to be the optimum density for inland open water cage culture.
本研究进行了 240 天，以评估基于生长特性、消化酶、肌肉成分、生化和生理反应的放养密度对罗非鱼幼鱼在热带内陆开放式网箱中的影响。将 30.35±1.08g 的罗非鱼随机分配到三个处理组中，即低密度、LSD（10m）、中密度、MSD（20m）和高密度、HSD（30m），每组重复三次。鱼每天投喂两次 CIFRI CAGEGROW®漂浮饲料（粗蛋白 28%，粗脂肪 4%）。在 LSD 中，鱼的生长和饲料效率更高（p<0.05），而 MSD 的产量更高。淀粉酶和蛋白酶活性降低，而脂肪酶活性随放养密度的增加而增加。肌肉粗蛋白和粗脂肪呈负相关。基于肌肉 pH 值、滴水损失和冷冻渗漏率，较高的放养密度会导致鱼片质量恶化。在拥挤条件下，血清中的应激生物标志物水平（葡萄糖、皮质醇、超氧化物歧化酶和过氧化氢酶）增加。血清中的谷氨酸草酰乙酸转氨酶和谷氨酸丙酮酸转氨酶在 HSD 中显著增加。血清蛋白水平随放养密度的增加而降低。在拥挤应激下，观察到体内离子失衡（Na、Cl 和 K）。基于生长特性和多种生物标志物反应，L. rohita@10m 被认为是内陆开放式网箱养殖的最佳密度。
