On-site evaluation of commercial-scale hybrid catfish production using cryopreserved blue catfish sperm

Authors: HU, E - Louisana State University; Bosworth, Brian; BAXTER, JEFF - Baxter Land Company; TIERSCH, TERRENCE - Louisana State University

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2014
Publication Date: 1/29/2014
Citation: Hu, E., Bosworth, B.G., Baxter, J., Tiersch, T.R. 2014. On-site evaluation of commercial-scale hybrid catfish production using cryopreserved blue catfish sperm. Aquaculture. 426-437:88-95.

Interpretive Summary: Cryopreservation is an effective tool for conservation of genetic resources and is becoming increasingly used worldwide with aquatic species. We examined factors relevant to use of cryopreserved (frozen) blue catfish sperm for commercial-scale production of hybrid catfish (channel catfish female x blue catfish male). U.S. production of hybrid catfish has increased dramatically over the last few years due to the hybrids’ superior growth, disease resistance and meat yield. However, hybrid production requires that male blue catfish be sacrificed to obtain sperm and this sperm is used fresh and therefore has a limited shelf-life. High-throughput cryopreservation offers efficient, long term storage and use of blue catfish sperm, and provides commercial hybrid producers advantages in resource utilization and hybrid fry production efficiency. A series of trials were conducted on a commercial farm using cryopreserved sperm to produce hybrid catfish fry. We found that cryopreserved sperm was equal to fresh sperm for fry production based on trials with over 2 million eggs. We also found no difference in average fertility when we used cryopreserved samples from individual males or cryopreserved samples from several males pooled prior to freezing. We suggest pooling sperm from several individual blue male catfish prior to freezing to minimize potential issues related with using cryopreserved samples from individual males (sterile male, contamination of a single male’s sample) on fry production. High-throughput cryopreservation of blue catfish sperm provides new capabilities and can maintain sperm quality sufficiently to support commercial hybrid production.

Technical Abstract: Cryopreservation is an effective tool for conservation of genetic resources and is becoming increasingly used worldwide with aquatic species. Broadening the application of this technology to a commercial scale through high-throughput approaches has become essential for use with aquatic species. This study addressed high-throughput sperm cryopreservation of blue catfish at a commercial level. Our objectives were to: 1) optimize the sperm volume used for thawed sperm; 2) evaluate commercial application of high-throughput cryopreserved sperm with standard hatchery techniques, and 3) evaluate the fertility relationship between individuals and pooled samples. The results showed that a doubling of the previously established volume did not produce significant improvement in fertilization. The working volume of thawed sperm (2 ml at a concentration of 1×109/ml for batches of 100-150 ml channel catfish eggs) was practical. There was no significant difference in fry production after artificial fertilization of 2 million eggs with cryopreserved or fresh sperm. Pooled samples performed statistically the same as individual fertility by the same fish in terms of percent neurulation of eggs. This sperm is valued as a genetic material for hybrid catfish production, and cryopreservation makes genetic material management possible. This study initiates industrialization of this technology for use with aquatic organisms, and because the technology can be generalized, expands the opportunities for application to other species. High-throughput cryopreservation of blue catfish sperm provides new capabilities and can maintain sperm quality sufficiently to support commercial hybrid production.