Cryopreservation of European flat oyster (Ostrea edulis) larvae using a controlled-rate freezer

• Published in: Aquaculture 2024-06, Vol.587, p.740887, Article 740887
• Main Authors: Horváth, Ákos, Jug-Dujaković, Jurica, Radočaj, Tena, Barić, Oliver, Špelić, Ivan, Balogh, Réka Enikő, Lefler, Kinga Katalin, Kitanović, Nevena, Marinović, Zoran, Urbányi, Béla, Gavrilović, Ana
• Format: Article
• Language: English
• Subjects: Controlled-rate freezer; Cryopreservation; Cryoprotectants; European flat oyster; Larvae
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2024.740887

Larvae of the European flat oyster (Ostrea edulis) were cryopreserved using two protocols originally developed for other bivalvian species with several modifications. Culture of the European flat oyster went through several setbacks due to parasitic diseases, thus, assisted reproductive technologies such as larval cryopreservation can aid in prompt restoration of lost populations and thus facilitate farming of the species. Veliger larvae were diluted in two basic extenders (0.4 M trehalose or 0.4 M sucrose) supplemented with ethylene glycol (EG), dimethyl-sulfoxide (DMSO) or propylene glycol (PG) in concentrations of 10–20% with or without the addition of polyvinylpyrrolidone (average MW-40,000; PVP-40). Larvae were loaded into 0.25-ml or 0.5-ml straws and cryopreserved in a controlled-rate freezer using two slow cooling profiles. Assessment of larval survival 20 min or 24 h post-thaw revealed that the cooling profiles and the type of extender used did not have a significant effect on survival rates. On the other hand, the type of cryoprotectant, straw volume and the time of assessment had a significant main effect on larval survival percentages (p