Cryopreserved Germplasm Case Study: Common Carp

The common carp (Cyprinus carpio) is a globally significant aquaculture species, particularly in Central and Eastern Europe. To enhance breeding programs and ensure genetic diversity, the application of cryopreserved sperm has been explored. A notable study conducted at a Hungarian aquaculture facility investigated the efficacy of using cryopreserved common carp sperm in large-scale hatchery propagation.

In this study, sperm was collected from mature male common carps and cryopreserved in 5 mL straws using an extender method previously tested for this species. The cryopreservation process involved freezing the sperm with specific extenders and cryoprotectants to maintain cell viability during storage at ultra-low temperatures. Post-thaw, sperm motility was assessed using a computer-assisted sperm analysis system to determine the effectiveness of the cryopreservation protocol.

The fertilization trials compared the performance of cryopreserved sperm to that of fresh sperm. Results indicated that while fresh sperm exhibited higher motility parameters, the cryopreserved sperm still achieved a moderate hatching rate of 42%. Importantly, no significant differences were observed in the overall malformation rates between larvae produced from fresh and cryopreserved sperm. Throughout the pre-nursing and grow-out periods, the growth performance—measured in terms of body weight and total length—of fish from both groups was comparable. By the end of the grow-out stage, survival rates were also similar, with 96% in the cryopreserved group and 95% in the fresh sperm group.

The successful application of cryopreserved sperm in common carp aquaculture signifies a promising advancement in fish breeding practices. It provides a practical approach to maintaining genetic diversity, improving breeding efficiency, and supporting the sustainable production of this economically important species.