Ammonia is a factor restricting production in aquaculture systems, hindering fish production adversely. A detailed study was planned and conducted using a static water system to scrutinize the toxic effects of unionized ammonia (UIA) on patho-physiological responses of O. belangeri, an important aquaculture candidate for diversification of freshwater aquaculture and endangered species, when exposed to different sub-lethal concentrations of UIA. The 96-h LC₅₀ value of UIA on O. belangeri was found to be 1.36 mg l⁻¹. The sub-lethal toxicity test with three UIA concentrations, i.e., 0.27, 0.68, and 0.80 mg l⁻¹ at different exposure period of 24, 48, 72, and 96-h revealed that exposure to UIA induced a significant reduction in hematological parameters, such as total erythrocyte count (TEC), total leukocyte count (TLC), hemoglobin (Hb), and hematocrit (Hct). Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) also substantially declined due to UIA exposure. Among biochemical parameters, blood glucose, serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and Na⁺ and K⁺ ion increased significantly. In contrast, serum protein, alkaline phosphatase (ALP) and serum albumin notably decreased due to ammonia exposure. Fish exposed to different UIA concentrations for 96-h displayed several histopathologic alterations in the gill and kidney tissues. Gill tissues showed several lamellar deformations, while kidney tissues showed significant changes at the level of the glomerulus and tubular epithelium. The NOEL or safe concentration of UIA for this particular fish species was found to be 0.07 mg l⁻¹. The observed patho-physiological alterations in the present study establish the most detail insights of UIA stress in O. belangeri and will enhance the international literature on UIA toxicity.

氨是限制水产养殖系统产量的一个因素，不利于鱼类生产。详细研究计划和进行使用静态水系统审议非离子氨（UIA）的上的病理生理反应的毒性作用O.鼩当暴露于不同的，一个重要的水产养殖候选淡水养殖的多样化和濒危物种， UIA的亚致死浓度。发现UIA在贝加利橙上的96-h LC ₅₀值为1.36 mg l ^-1。使用三种UIA浓度，即0.27、0.68和0.80 mg l ^-1的亚致死毒性试验在24、48、72和96小时的不同暴露时间下，暴露于UIA会引起血液学参数的显着降低，例如总红细胞计数（TEC），总白细胞计数（TLC），血红蛋白（Hb）和血细胞比容（Hct）。由于UIA暴露，平均红细胞体积（MCV），平均红细胞血红蛋白（MCH）和平均红细胞血红蛋白浓度（MCHC）也大大降低。在生化参数中，血糖，血清谷氨酸丙酮酸转氨酶（SGPT），血清谷氨酸草酰乙酸转氨酶（SGOT）以及Na ⁺和K ⁺离子显着增加。相反，由于氨暴露，血清蛋白，碱性磷酸酶（ALP）和血清白蛋白显着降低。暴露于不同UIA浓度下96小时的鱼在ill和肾组织中表现出几种组织病理学改变。组织显示出若干层状变形，而肾组织在肾小球和肾小管上皮水平上显示出显着变化。发现该特定鱼类的UIA的NOEL或安全浓度为0.07 mg l ^-1。在本研究中观察到的病理生理变化建立了贝加莱鱼中UIA应激的最详细见解，并将加强关于UIA毒性的国际文献。