Spotted wolffish (Anarhichas minor) sperm cryopreservation in 5-mL cryovials

• Published in: Fish physiology and biochemistry 2021-06, Vol.47 (3), p.697-701
• Main Authors: Beirão, J., Flengstad, S., Babiak, I.
• Format: Article
• Language: English
• Subjects: Anarhichas minor; Animal Anatomy; Animal Biochemistry; Animal Physiology; Aquaculture; Biological fertilization; Biomedical and Life Sciences; Cells; Cryogenic engineering; Cryopreservation; Fish hatcheries; Freezing; Freshwater & Marine Ecology; Hatcheries; Histology; Life Sciences; Liquid nitrogen; Melting; Morphology; Nitrogen; Spawning; Spawning seasons; Sperm; Spermatozoa; Thawing; Zoology
• ISSN: 0920-1742; 1573-5168
• DOI: 10.1007/s10695-020-00837-1

In spotted wolffish Anarhichas minor aquaculture, cryopreservation is used to secure sperm availability throughout the entire spawning season. Under current protocols, sperm is cryopreserved in 0.5-mL straws. This implies thawing a considerable number of straws for insemination with cryopreserved sperm. In this work, we scale up the spotted wolffish sperm cryopreservation procedure through the development of a protocol for sperm cryopreservation in 5-mL cryovials. Different freezing (distances from the liquid nitrogen surface) and thawing rates were tested. The best results were obtained with cryovials frozen at a distance of 1.5 cm from the liquid nitrogen surface and thawed either at 15 or 10 °C for 4 and 6 min, respectively. Under these conditions, similar percentage of motile cells, sperm velocity and percentage of viable cells were obtained in comparison with the sperm cryopreserved in the traditional 0.5-mL straws. This protocol will facilitate the process of insemination with cryopreserved sperm in the spotted wolffish hatcheries.