Journal of Aquaculture Research & Development

Abstract

The Optimum Dose of Thyroxine Hormone Supplementation in Broodstock Mud Crab (Scylla Serrata) to Accelerate Ovarian Maturation

Heppi Iromo*,Zairin Junior M,Agus Suprayudi M,Wasmen Manalu

This experiment was designed to study the optimum dose of thyroxine supplementation in accelerating ovarian maturity in broodstock mud crab (Scylla serrata). The production of mud crab is very low since the production system relies on the natural harvesting that has not applied aquaculture technology optimally. The low productivity in natural culture is thought to be related to the low magnitude of biological process and metabolism that support optimum reproduction system such as the slow and low rate of vitellogenesis. The ovarian maturity is started by the synthesis and the release of vitellogenin into the hemolymph and then transported to the ovum to be used as a precursor of egg yolks synthesis. The thyroxine hormone is found in the follicle and assists the process of yolk absorption. This study used 4 levels of thyroxine supplementation i.e., 0 μg/g BW (control), 0.05 μg/g BW, 0.10 μg/g BW and 0.15 μg/g BW. In general, the supplementation of thyroxine significantly improved the rate of ovarian maturity (P<0.05). Supplementation of thyroxine at the dose of 0.10 μg/g BW gave the highest rate of ovarian maturity. Supplementation of thyroxine increased yolk absorption during ovarian maturity. It was also found that thyroxine supplementation increased concentrations of protein and RNA/DNA during ovarian maturity.