Cryopreservation of Spermatophore of the Fresh Water Shrimp,macrobrachium Rosenbergii

Spermatophores were removed from the sternum of a female Macrobrachium rosenbergii immediately after mating, and equilibrated in either fresh water or physiological saline, both containing 10% glycerol. After 10 to 60 minutes equilibra tion, these spermatophores were pre-frozen in liquid nitrogen (LN2) vapor and submerged in LN2. The spermatophores were then thawed by directly putting them into warm water, and attached to the sternum of other females using a glue. Successful fertilization was observed in cases where the spermatophores were equilibrated in fresh water for 15-30 minutes. At 10 minutes equilibration, most of the spawned eggs were not fertilized. Furthermore, fertilized eggs were not obtained without pre-freezing, or where spermatophores were equilibrated in physiological saline.