2010/755 Sperm cryopreservation in Australian farmed greenlip (Haliotis laevigata) and blacklip (H. rubra) abalone

By Yibing Liu

Sperm cryopreservation is a proven technique to overcome similar issues and sperm collected from wild Greenlip Abalone has been investigated and 90% post-thaw sperm fertilization rates have been achieved. Nevertheless, when the developed protocol was applied to sperm from farmed stocks, low and highly variable results were observed, hindering its application. The Australian abalone aquaculture industry now relies entirely on domesticated farmed abalone as broodtsock. Therefore, understanding factors causing this discrepancy, and development of sperm cryopreservation techniques suitable for Australian farmed abalone species, were the focus of this PhD project.

This thesis explored the differences in cryo-sensitivities between sperm from farmed and wild abalone and identified the broodstock physiological conditions best suitable for sperm cryopreservation in farmed abalone. Investigation on the methods for sperm quality assessment, sperm component integrity and organelle functionality were investigated. In Greenlip Abalone, broodstock physiological conditions, such as broodstock age and sperm collection time over a natural spawning period, were also evaluated.

Results from evaluation of broodstock physiological conditions in farmed Greenlip Abalone showed that sperm collected at the middle of a natural spawning period had a better ability to tolerate the cryopreservation processes than those collected at the beginning or at the end of a natural spawning period. Sperm from farmed abalone were more sensitive to cryopreservation treatment than wild counterparts. This research developed sperm cryopreservation techniques for Australian farmed Greenlip and Blacklip Abalone.