Abstract

This experiment aimed to study the acclimatization of mandarin fish fry, using squid paste, betaine, and black soldier fly larvae slurry as feeding agents to investigate their effects on the growth, physiological and biochemical characteristics, and acclimatization rate of mandarin fish larvae. The results showed that during the acclimatization process of mandarin fish fry, the weight gain rate of mandarin fish fed with black soldier fly larvae slurry and squid paste was higher than that of the control group; squid paste significantly affected the specific growth rate of mandarin fish. The feed coefficients for the three treatments were all lower than those of the control group, while the survival rate and acclimatization rate were both higher than those of the control group. In terms of physiological and biochemical indicators: the addition of three feed additives significantly increased the crude protein content in juvenile mandarin fish, while the addition of black soldier fly pulp significantly increased the crude fat content in the body. Squid paste significantly increased the activity of alanine transaminase and gamma-glutamyl transferase in the blood, and also significantly reduced the total protein content in the blood. Both squid paste and betaine significantly decreased the activity of alanine transaminase in the liver, but betaine also significantly reduced the activity of gamma-glutamyl transferase in the liver. Black soldier fly pulp and betaine both significantly increased the activity of glutamate dehydrogenase in the liver. In summary, all three feed additives can improve the efficiency of domestication. Among them, squid paste is most effective in promoting early growth performance and has excellent physiological metabolic indicators. Betaine, on the other hand, reduces the metabolic burden on the liver during the domestication process of mandarin fish. Therefore, it is worth considering the combination of squid paste and betaine for further validation.