Mud crab (Scylla tranquebarica) is an important aquaculture species, especially in Southeast Asian Countries. However, the larval rearing of this species faces problems resulted in low survival caused not only by intensive cannibalism but also by prolonged in larval rearing period. The stocking density
during early life stages is proposed to influence the crablet production in the larvae rearing tanks. The objective of this research was to evaluate the effect of stocking densities on larval stage development and crablet production of, S. tranquebarica. Four different initial stocking densities of larvae were tested using 200 L fiber glass tank, namely: A). 30 ind,/L, B). 45 ind./L, C). 60 ind./L and D). 75 ind./L. The larvae were fed on rotifer, Brachionus sp, and Artemia nauplii with addition of commercial diet. Water exchanged in the rearing tank was performed since seven days post hatching (dph) to 20 dph at a rate of 10 to 40%. Larvae from each experimental tank were sampled periodically (2 to 4 days interval) to calculate larvae population, larvae development index (LDI). Megalopa occurrences index
(MOI), and crablet production are also calculated. The treatment B and D are showed the highest of LDI and MOI which are significantly different (P<0.05) to the other treatments. Furthermore, the highest of crablet production was obtained from treatment D = 495.3+22.48 ind./tank, which was significantly higher (P<0.05) compared to treatment A (48.5+4.94 ind./tank), treatment B (167.5+10.61 ind./tank) and treatment C (218.33+10.41 ind./tank). Therefore, the stocking density of 75 ind./L is optimum for S. tranquebarica larvae and recommended to be applied for commercial larvae production in the hatchery.
Penulis: Gunarto,* and Sulaeman
