An eight-week study was conducted to determaine the suitable rate of substituting larval mealworm (Tenebrio molitor), as an alternative protein source for Asian Seabass (Lates calcarifer) and to determine its effects on growth performance, carcass composition and hematological indicators. One hundred and forty-four fish with a mean weight of 54±0.5g and a mean length of 16.55±0.08cm were randomly distributed into four groups with three replicates, each containing twelve fish. At the beginning of the experiment, there was no statistically significant difference in terms of weight among the experimental units. For eight weeks, the fish were fed with experimental diets, control treatment (without insect meal) and treatments containing 20%, 40%, and 60% mealworm to replace the fish meal. Groups were fed the experimental diets at a rate 3% of body weight, three times daily. At the end of the experiment, there were no statistically significant differences in specific growth rate (SGR), feed conversion ratio (FCR), feed intake (FI), protein efficiency ratio (PER), productive protein value (PPV), condition factor (CF), or hepatosomatic index (p>0.05) amongst the Asian seabass fed diets containing different levels of the yellow mealworm. However, there were differences between the treatments in terms of final body weight (FBW), body weight increase (BWI) and viscerosomatic index (VSI) (P <0.05). A chemical examination of the fish carcasses revealed substantial variations in lipids across the treatments (P <0.05). The number of red blood cells, mean red blood cell volume (MCV) and mean blood hemoglobin (MCH) did not show any significant differences between the treatments (P>0.05). While the number of white blood cells, the mean concentration of hemoglobin in red blood cells (MCHC), hemoglobin (Hb) and hematocrit (Hct) showed a significant difference (P<0.05). Triglyceride (TG), glucose, cortisol, lysozyme, and alkaline phosphatase (ALK) levels in plasma biochemistry analysis were rised with the increasing inclusion of TM in the diet (P<0.05). While there were no appreciable variations in the levels of SOD and MDA activity among the dietary groups (P>0.05), the amount of TM in diets increased the activity of GPX and CAD. The results of intestinal microbial culture of Asian Seabass fed with varied levels of TM revealed substantial differences in the number of bacterial colonies. The maximum number of colonies was seen at 20% Treatment. The activity of amylase, protease, trypsin, chymotrypsin, lipase, and alkaline phosphatase in Asian Seabass fed with various doses of TM revealed that the digestive enzyme activity of the fish was significantly different (P<0.05). The 60% treatment had the highest enzyme activity for amylase protease, but the 20% diet group had the highest enzyme activity for alkaline phosphatase. Since the use of Tenebrio molitor meal had no negative impacts on growth performance, it can be used as an alternate protein source in the diets of Asian sea bass up to 40%, however, further research is needed to eva‎luate the efficiency of economic production and carcass quality.

عيسي ابراهيمي درچه , يزدان كيواني

اميرحسين جلالي

نصرالله محبوبي صوفياني , فاطمه پيكان حيرتي , اميرحسين مهدوي