In vitro culture and cryopreservation of Uronema marinum isolated from farmed New Zealand groper (Polyprion oxygeneios)

An in vitro culture method was developed for the ciliated protozoa Uronema marinum isolated from New Zealand aquacultured groper (Polyprion oxygeneios). Both formulated media and sterile seawater supplemented with homogenised fish tissue as a food source supported growth of U. marinum achieving cell densities of up to 1 × 105 cells/mL in culture. A cryopreservation method based on a cryomix formula of 20% glycerol, 10% fetal bovine serum and 70% cultured U. marinum, incorporating a slow freeze method to − 80 °C, then liquid nitrogen storage, allowed cryogenic storage of cells and successful re-culture up to 12 months in storage.