New Publication: Embryos and Ovarian Tissues of South American Neotropical Fish: Current State of Development.

Cell deterioration is stopped in biological tissues stored at sufficiently low temperatures, such as below –150°C (Leibo and Mazur 1971). Thus, this cessation of biological time allows cells to be preserved indefinitely. Cryopreservation of maternal and paternal gametes is an essential technique for establishing biological material banks, as it preserves the genetic variability of the population and maintains the characteristics of the species. Cryopreservation of fish sperm is widely used, but some issues concern the female genome (embryo and oocyte). Among them is the high sensitivity to cold, the presence of compartments, the low permeability to the membrane, and the high amount of intracytoplasmic lipids (Tsai and Lin 2012; Diwan et al. 2020). These structural differences happen mainly because of external fertilization. Thus, over the
years, several studies have been conducted to overcome these problems and preserve the maternal genetic material of fish. Therefore, this chapter will present the current state of development of embryo and ovarian tissue cryopreservation techniques for South American Neotropical fish species and their prospects.