High-throughput sperm cryopreservation of aquatic species

Abstract

The goal of this dissertation was to integrate multiple disciplines for application of high-throughput sperm cryopreservation to aquatic species. The blue catfish Ictalurus furcatus was selected for research due to its role in production of hybrid catfish with eggs from channel catfish Ictalurus punctatus. A high-throughput cryopreservation pathway was developed by systematically evaluating each process factor and using automated processing systems. Large quantities of cryopreserved sperm produced from this protocol were evaluated in commercial-scale hatcheries in cooperation with aquaculture producers. To develop production for commercial requirements, quality characteristics of materials and products were identified and recorded during processing and analyzed using industrial engineering methods to regulate quality. More than 1 million channel catfish eggs from 300 females were fertilized with thawed sperm, which was larger than any previous large-scale fertilization trial performed in fish. This demonstrated that the fertilization capability of cryopreserved sperm was equivalent to fresh sperm in production of hybrid fry. Quality regulation was presented within a quality assurance plan designed specifically for this process using quality standards (specifications) and quality variation data (quality control). This quality assurance plan is potentially the first of its kind for cryopreserved sperm of any species. After being scaled up by automation and standardized by the quality assurance plan, the cryopreservation process produced reliable products for hatcheries. Proper use of these products (i.e., as a dose of 3704 eggs/straw) can provide a basis for industry standards for artificial spawning. A quantitative evaluation was developed based on the defined dose and the production efficiency. To increase the efficiency for large-scale production, simulation model computing was used to create a virtual process. The simulation model was validated based on the existing process, and provides a valuable tool for future improvements. This dissertation took the initiative to apply high-throughput cryopreservation in aquaculture and expand the process from planning to operation at the production line, to terminal use of products by customers. This enables cryopreserved sperm to become a practical form of genetic resources applicable for aquatic genetic improvement and conservation.