Cannibalism control of Asian seabass Lates calcarifer fry by melatonin hormone administration

Cannibalism is one of the causes low survival rate white snapper fry due to its aggressiveness. Melatonin is a hormone that can modulate aggressive interactions in fish. This study aims to evaluate effect of melatonin hormone on the level cannibalism sea bass. This study used completely randomized design (CRD) consisting of four treatments and three replications, namely control (without melatonin hormone administration), melatonin doses of 5, 10, and 15 µg/g fish. Hormone administration was done orally through feed supplementation. Sea bass fry used were 2.82 ± 0.41 cm average length and 0.53 ± 0.08 g average weight. Stocking density was 2 fish/L. Sea bass were reared for 30 days with flow through system and fed three times a day in restricted manner (Feeding rate 15%). The results showed the administration of melatonin hormone can reduce level cannibalism, increase melatonin hormone levels, increase estradiol 17β hormone, and have no effect on body glucose levels sea bass. Melatonin dose 10 µg/g fish can reduce level cannibalism by 40.67% (P