Cryopreservation of aquatic invertebrate semen: a review

Research on cold storage and cryopreservation of aquatic invertebrate spermatozoa is reviewed in this paper. A few studies are available on the cryopreservation of aquatic invertebrate semen. These have been limited to echinoderms (sea urchin, sand dollar and starfish), molluscs (oyster and abalone), polychaetes and crustacea (shrimp and crab). In fact, only about 30 species have been investigated to date, and research has been primarily concentrated on the spermatozoa of the oyster. Although aquaculture of decapod crustaceans has become very important, information on sperm biology is limited, and sperm preservation techniques are sparse. The sperm of decapod (shrimp and crab) crustaceans are aflagellate and non-motile, and eggs are not readily available. One of the main reasons for the problems in the cryopreservation of crustacean sperm is considered to be the lack of reliable viability evaluation. Conclusions and new avenues of future research are proposed.