CRYOPRESERVATION OF REPRODUCTIVE PRODUCTS AS AN EFFECTIVE METHOD FOR PRESERVING THE BIODIVERSITY OF STURGEON FISH SPECIES (REVIEW)

Purpose. In recent years, cryopreservation of reproductive products has widely been used as one of the accessible and in some cases the only ways of preserving and supporting the number of endangered fish species including sturgeon fish species. Currently, the method of cryopreservation is represented by various techniques and ways using individual and species approaches. Numerous publications on the issue of fish sperm cryopreservation mostly contain inconsistent results and ambiguous data. Thus, the analysis of the existing information about principles and methods of fish sperm cryopreservation is an important issue for further studies. Moreover, summarizing the existing information will enable us to plan the experiment more efficiently and reasonably and to get the desired outcomes with higher reliability. Findings. The study presents main principles of widely used methods of fish sperm cryopreservation, the analysis of main factors of influence on outcomes of freezing or unfreezing as well as the analysis of results received when using various ways and methods of cryopreservation. Besides, the paper shows the importance of forming and full functioning of fish sperm cryobanks. Originality. The paper summarizes the existing information on the issue of fish sperm low temperature cryopreservation. The information is given in the form of successive presentation of the research outcomes received at each point of freezing or unfreezing when using different techniques as well as results of different factors influence on it. Moreover, a review of achievements in the field of cryopreservation and main principles of forming fish sperm cryobanks are given. Practical value. The presented review of traditional and modern literature data in the issue of cryopreservation can be used when planning, redesigning and experimenting fish sperm freezing or unfreezing.