Genital reversal of betta fish by immersion using steroid extract of sea urchins

Abstract

Abstract Sea urchin, Diadema setosum is a potential fishery commodity with high economic value. It contains a steroid compound as an aphrodisiac in male monosexes (masculinization). In aquaculture usually used 17α-methyl testosterone, but it was difficult to decompose or it contaminated with carcinogens and pollutants. Therefore, it needs to be replaced with safer natural hormones from sea urchin. Betta sp. is an ornamental fish with high demand because of its colorful, diverse tail shapes, and price of male is higher than female, so that male cultivation is beneficial. This study aimed to utilize steroid compounds of sea urchin gonad extracts in masculinization of betta fish. In particular, it is to examine the steroid compounds by providing different doses and soaking times to the formation of male. The study was conducted using a completely randomized design method which was further classified into two stages. In first stage, the soaking dose was 0, 2, 4, 6 and 8 mg L-1 for 12 h, while in stage II, the immersion duration was 0, 12, 18, 24 and 30 h at a dose of 4 mg L-1 in larvae aged 2 weeks. Each treatment was repeated 3 times, and data were analyzed using Anova as well as with the LSD test at the level of 5%. The results showed that on the immersion in dose of 4 mg L-1, the highest male individual of 84.10% was formed. Also, a dose of 4 mg L-1 was significantly different from the control and 6 mg L-1, but it was not significantly different from that of 2 and 8 mg L-1. The difference in immersion time significantly affected the success of male monosex formation and the duration of 12 h in dose of 4 mg L-1 sea urchin extracts showed the highest percentage of 84.00%.