Majhi Snigdha S, Singh Soibam Khogen, Biswas Pradyut, Debbarma Reshmi, Parhi Janmejay, Khatei Ananya, Mangang Yumnam Abungcha, Waikhom Gusheinzed, Patel Arun Bhai
College of Fisheries, Central Agricultural University (Imphal), Lembucherra, Tripura West 799210, India.
Fish Shellfish Immunol Rep. 2023 Jul 20;5:100112. doi: 10.1016/j.fsirep.2023.100112. eCollection 2023 Dec 15.
Scientific research into fish wellness is critical, and the concerns about crowding-related stress due to increased stocking density are inevitable. Taking this into consideration, the study defines the physiological signature of (Butter catfish) in a biofloc system when subjected to varying levels of stocking density. Fish (mean weight = 1.21 ± 0.08, = 600) were randomly stocked in 40-L glass aquaria at stocking densities of 0.5 g/L (T1), 1 g/L (T2), 1.5 g/L (T3), and 2 g/L (T4) and fed a 35% protein diet. After the 90-day trial, the physio-biochemical, molecular, and tissue-level changes were assessed. An integrated biomarker response (IBR) analysis for the key stress indicators aided us in better understanding them. There was a significant difference in blood count between T1 and T4 (total erythrocyte count, hemoglobin, and packed cell volume). T1 had higher levels of globulin and total plasma protein, but T2 had higher levels of albumin. Only in T1 did the respiratory burst and lysozyme activity appear to be higher (p < 0.05). Increased stocking densities had a significant impact on the liver function enzymes, GOT and GPT (p < 0.05). In comparison to lower densities (T1 & T2), higher stocking density (T3 & T4) was found to raise glucose and cortisol levels (p < 0.05). Antioxidant enzymes such as catalase, glutathione-S-transferase, and malondialdehyde were found to be more pronounced in lower density tissues (T1). Furthermore, the IBR plots show that lower densities have better health than higher densities. At higher stocking densities, mRNA expression of , IL-1, and IL-20 increased (p < 0.05) in kidney and liver tissues. The Nrf-2 and Tlr-9 genes were also upregulated. Also, when stocking density was increased, tissue-level histo-architectural changes were more pronounced than when stocking density was kept low. The findings of this study show that the welfare of Butter catfish cultured at high density in biofloc systems suffers from severe stress, and therefore draw more attention to the development of a species-specific standard rearing methodology in the pursuit of a profitable aqua-farming enterprise.
对鱼类健康的科学研究至关重要，而且由于放养密度增加而引发的与拥挤相关的应激问题不可避免。考虑到这一点，该研究确定了在生物絮团系统中，当胡子鲶（Butter catfish）处于不同放养密度水平时的生理特征。将鱼（平均体重 = 1.21 ± 0.08，n = 600）以0.5 g/L（T1）、1 g/L（T2）、1.5 g/L（T3）和2 g/L（T4）的放养密度随机放养在40升的玻璃水族箱中，并投喂蛋白质含量为35%的饲料。经过90天的试验后，评估了其生理生化、分子和组织水平的变化。对关键应激指标进行的综合生物标志物反应（IBR）分析有助于我们更好地了解它们。T1和T4之间的血细胞计数（总红细胞计数、血红蛋白和红细胞压积）存在显著差异。T1的球蛋白和总血浆蛋白水平较高，但T2的白蛋白水平较高。仅在T1中，呼吸爆发和溶菌酶活性似乎较高（p < 0.05）。放养密度增加对肝功能酶谷草转氨酶（GOT）和谷丙转氨酶（GPT）有显著影响（p < 0.05）。与较低密度（T1和T2）相比，较高放养密度（T3和T4）会使葡萄糖和皮质醇水平升高（p < 0.05）。发现过氧化氢酶、谷胱甘肽 - S - 转移酶和丙二醛等抗氧化酶在低密度组织（T1）中更为明显。此外，IBR图显示较低密度的鱼健康状况优于较高密度的鱼。在较高放养密度下，肾脏和肝脏组织中肿瘤坏死因子（TNF）、白细胞介素 - 1（IL - 1）和白细胞介素 - 20（IL - 20）的mRNA表达增加（p < 0.05）。核因子E2相关因子2（Nrf - 2）和Toll样受体9（Tlr - 9）基因也上调。而且，当放养密度增加时，组织水平的组织结构变化比放养密度保持较低时更为明显。本研究结果表明，在生物絮团系统中高密度养殖的胡子鲶福利受到严重应激影响，因此在追求盈利性水产养殖企业的过程中，应更加关注制定特定物种的标准养殖方法。
