Gonado Somatic Index in G5 Transgenic Mutiara Catfish (Clarias gariepinus) at Different Temperatures

Abstract

Temperature is one of the factors that can affect the maturity of the gonads in fish. This study aims to find out what is the best temperature for maturation of broodstock to prepare G5 transgenic mutiara catfish broodstock that are ready to hatch based on gonado somatic index (GSI) performance, relative fecundity, fertilization rate (FR), hatching rate (HR). The research was carried out in the Hatchery Building 4, Fisheries Biotechnology Laboratory, Faculty of Fisheries and Marine Sciences. The method used in this research is an experimental method with a complete randomized design (CRD), which consists of four treatments and three replicates. Treatment A: 26 ± 0.5 °C, B : 28 ± 0.5 °C, C : 30 ± 0.5 °C for transgenic catfish, C*: 30 ± 0.5 °C (for nontransgenic catfish) with maintenance for 8 weeks.  The reproductive performance of the female broodstock of G5 transgenic mutiara catfish with the highest relative fecundity was found in treatment B of kg/brood. The best temperature for gonad maturation was obtained in treatment B with a temperature of 28 ± 0.5 °C with  a gonadosomatic index value of  52.42 ± 5.93% for  females and 5.22 ± 0.17% for males. The spawning performance in the parent pair of treatment B produced the best relative fecundity, fertilization rate (FR), and hatching rate (HR), with values of 89,179 eggs/kg, 84.98 ± 5.01%, and 90.87 ± 3.12%, respectively.