Gryodactylus malalai is a monogenean ectoparasite that causes damage to the skins and gills of the infected fish. It is a viviparous organism and easily transmitted to other fish in an aquatic ecosystem resulting in huge biological and economical losses. The use of chemotherapeutics is the method adopted by farmers in the treatment, and control of monogenean infections. However, the use of these chemotherapeutics has been discouraged because they are costly, have residual effects on fish tissues, and contribute to environmental pollution. Thus, a substitute for synthetic chemotherapeutics needs to be investigated and developed. Effects of Mitracarpus scaber leaves extract (MSLE) on growth, antioxidants, immunity, and resistance of Nile tilapia, Oreochromis niloticus to G. malalai infestation have been examined. Four diets of 300 g/kg crude protein were formulated and fortified with MSLE at 0.0 (control), 2, 4, or 6 g/kg diet. Each diet was fed to Nile tilapia juveniles (3.5 ± 0.02 g) to noticeable satiation three times a day for 56 days. Then, fish were experimentally challenged using bath method by releasing the fish into a solution containing 40 G. malalai per liter for 14 days. The infected fish were observed for any clinical signs and mortality. It was observed that MSLE fortified-diets significantly enhanced the fish growth, feed intake and utilization, but no significant differences were observed in feed conversion ratio and fish survival rate. Further, intestinal villi length, villi width, and absorption area were markedly increased in fish fed MSLE-based diets. Also, hemato-biochemical, antioxidant, and immune indices were significantly improved in Nile tilapia fed dietary MSLE levels. After exposure of fish to parasitic infestation, mortality was significantly decreased in Nile tilapia fed with MSLE-based diets especially at 6 g MSLE/kg diet (5.0%); meanwhile fish fed with the control diet showed the highest mortality (62.9%). Thus, it was concluded that diets supplemented with MSLE promoted fish growth performance, antioxidants, and non-specific immunity of Nile tilapia. Also, resistance of Nile tilapia to G. malalai infestation were elevated when fed MSLE-fortified diets ranged from 5.5–6 g/kg diet.

Galaodactylus malalai是一种单外生寄生虫，会对受感染鱼的皮肤和g造成损害。它是胎生生物，很容易在水生生态系统中传播给其他鱼类，造成巨大的生物学和经济损失。农民使用化学疗法来治疗和控制单基因感染。但是，不建议使用这些化学疗法，因为它们价格昂贵，对鱼组织有残留作用并造成环境污染。因此，需要研究和开发合成化学疗法的替代品。的影响Mitracarpus scaber上生长，抗氧化剂，免疫和尼罗罗非鱼的电阻，叶提取物（MSLE）罗非鱼到已经检查了马拉热菌的侵染。配制四种300 g / kg粗蛋白日粮，并以0.0（对照），2、4或6 g / kg日粮的MSLE强化。每种饮食均喂食尼罗罗非鱼幼鱼（3.5±0.02克），每天吃三遍，持续56天。然后，通过将鱼释放到含有40 G. malalai的溶液中，使用浴法对鱼进行实验性 攻击每升14天。观察感染鱼的任何临床体征和死亡率。观察到MSLE强化饮食显着提高了鱼类的生长，饲料的摄取和利用，但在饲料转化率和鱼类成活率方面未观察到显着差异。此外，饲喂MSLE饲料的鱼的肠绒毛长度，绒毛宽度和吸收面积显着增加。此外，尼罗罗非鱼饲喂的膳食MSLE水平显着改善了血液生化，抗氧化剂和免疫指标。在鱼类受到寄生虫侵扰后，以MSLE为基础的日粮喂养的尼罗罗非鱼的死亡率显着降低，尤其是6 g MSLE / kg日粮（5.0％）；同时，以对照饮食喂养的鱼死亡率最高（62.9％）。从而，结论是，补充MSLE的饮食可促进鱼的生长性能，抗氧化剂和尼罗罗非鱼的非特异性免疫力。此外，尼罗罗非鱼对饲喂MSLE强化日粮的饮食范围为5.5–6 g / kg饮食时，马拉热菌的侵染率升高。