Artificial crablets production of orange mud crab, scylla olivacea (Herbst, 1796) through in-vitro fertilization technique

Abstract

Crablets production in mud crab, genus Scylla is highly depends on the depleted wild crablets supply. Artificial crablets production through in-vitro fertilization technique can be an alternative for the crablets production of this mud crab. Therefore, this study was conducted to explore the artificial crablets production through in-vitro fertilization technique on orange mud crab, Scylla olivacea through the determination of (1) Fertilization rate and (2) Embryonic developments from the manipulation of sperm mass with Stage 4 ovary. The sperm mass were collected from the spermathecae of mature females, as well as from the vas deferens of males and allowed to fertilize the Stage 4 ovary in the Ca-F saline medium. Fertilized ovary were incubated in artificial seawater with controlled salinity (28-30 ppt) and temperature (28-30°C in water bath). Observation on fertilization rate and embryonic development were observed daily. Fertilization Membrane (FM) was developed when the ovary was fertilized. However, the embryos could only develop until Day 5 at most. Subsequently, FM could not be maintained and started to deteriorate resulting the embryos to lose their form. Further development could not be observed after Day 5. Manipulation of sperm from vas deferens (male) shows lower fertilization rate than spermathecae (female). Present study has proven that artificial crablets production S. olivacea through in-vitro fertilization technique from the manipulation of sperm mass with Stage 4 ovary was a success.