The effect of ice trash fish, Leiognathus equula (Forsskål, 1775) (Percomorphi, Leiognathidae) and oyster, Crassostrea iredalei (Faustino, 1932) (Ostreida, Ostreidae) on the growth and mating of the mud crab, Scylla paramamosain Estampador, 1950 (Brachyura, Portunidae), cultured in a controlled tank

Abstract

Abstract The aim of this study was to determine the most suitable kind of feed for the mud crab, Scylla paramamosain, to grow from juvenile to broodstock size and to monitor their monthly size and growth rate, as well as to (1) record them reaching maturity and (2) their subsequent mating frequency. For this research, a Complete Randomized Design was used with three treatments. Each treatment was carried out with 40 individuals. The crabs are usually grown in 90 m3 concrete tanks. The three feeds tested were: (A) trash fish, Leiognathus equula, (B) a combination of that ice trash fish and oyster meat from Crassostrea iredalei, and, (C) that same oyster meat only. The feed was always given at 3-10% of total body weight/day. Newly adult male crabs were selected for mating with a newly adult female crab. The male crabs fed treatments B and C grew faster than male crabs fed treatment A. While the female crabs fed treatment C grew significantly faster than female crabs fed treatment A (), but not significantly than the female crabs fed treatment B (). A total of 30 female crabs were followed in mating from July 2020 to January 2021, and the highest mating intensity was found from September to October 2020. The present study indicates that mud crabs grow fast when they are fed treatment C, i.e., oyster meat only.