Cryopreservation of finfish and shellfish gametes and embryos

Advances in research on cryopreservation of gametes and embryos of aquatic organisms are modest compared with work done in terrestrial animals and pla nts. While sperm has been successfully cryopreserved in a number of culture d finfish and shellfish species, utilization at the farm level is still ver y limited. Modest success has been achieved in the cryopreservation of shel lfish embryos and early larvae. On the other hand, cryopreservation of finf ish ova and embryos has not been successful so far. Unlike shellfish eggs a nd embryos, finfish ova and embryos are large, contain a large amount of yo lk and are covered with a relatively thick chorion. Uniformity in the penet ration of conventional cryoprotectants and in cooling during the freezing p rocess has not been attained in these large and dense specimens. Just as cryopreservation has many practical applications in breeding terres trial plants and animals, cryopreservation also offers the same potential i n the artificial propagation of many aquatic animals. Furthermore, cryopres ervation has a significant role in such concerns as aquatic biodiversity, e co-toxicology, and environmental conservation. This paper reviews the recent advances in finfish and shellfish gamete and embryo cryopreservation. Work done in the authors' country is discussed sep arately from those in the other countries. Future cryopreservation research in aquatic animals is directed towards overcoming the problems posed by fi nfish ova and embryos using very recent technical innovations. The wide app lication of cryopreservation in fish farming and in the preservation of aqu atic animals in general is encouraged. (C) 2001 Elsevier Science B.V. All r ights reserved.