Progress in research on cryopreservation technology for echinoderm sperm

Abstract:

Echinoderms hold the highest evolutionary status among the invertebrates and some species in the class Holothuroidea (sea cucumber) and Echinoidea (sea urchin) have very high economic and nutritional values. However, because of the impact of human activities, the number and biodiversity of several echinoderm species have severely declined, and germplasm degradation has been especially prominent in recent years, mainly manifesting as slow growth, frequent diseases, and low survival rates. Therefore, the preservation of germplasm resources is critical. Cryopreservation is an important method for the long-term preservation of germplasm resources. It has the advantages of breaking through geographical isolation, realizing distant hybridization, protecting germplasm resources, solving the problem of germplasm degradation, and protecting endangered species. This article reviews the progress in research on the cryopreservation of sperm of three major echinoderms (sea urchins, sea cucumbers, and starfish), and describes the various steps in sperm cryopreservation processes, such as sperm collection, extender and cryopreservation preparation, balance, cooling, thawing, and quality evaluation, to provide a ready reference for the future research and the industrial application of cryopreservation to echinoderm germplasm resources.