Development of a Novel Cold-tolerant, Disease-resistant Shrimp by Intraspecific Hybridization

The purpose of this project is to develop a new line of cold-tolerant, disease-resistant shrimp which will provide distinct commercial advantages to shrimp farmers in non-tropical climates, such as the United States, where colder water temperatures and pathogens restrict shrimp production. Successful development of this novel shrimp line will allow U.S. shrimp farmers to significantly increase production and offset a large trade imbalance due to imported shrimp products. During Phase I, Kona Bay Marine Resources (Kona Bay) created a new line of shrimp using intraspecific hybridization of two pure-bred lines, the Kona line noted for its cold tolerance and a line resistant to Taura Syndrome Virus (TSV-R line). All three lines (Kona, TSV-R, and Hybrid) were evaluated for growth and survival in cold (~20oC) and warm (~28 oC) water, as well as for resistance to four different isolates of TSV. Results indicate that growth and survival of shrimp from the Hybrid line were greater than growth and survival of shrimp from the Kona and TSV-R lines in cold water. Superior growth and pond survival of shrimp from the Hybrid line were more marked at the lower water temperature, indicating that the Hybrid line is less sensitive to temperature differences. Survival of shrimp from the Hybrid line was approximately the arithmetical mean survival of the Kona and TSV-R lines after TSV exposure. In summary, the Hybrid line created during Phase I research is commercially superior to either pure-bred line in all traits except TSV resistance. The objective of the Phase II proposal is to identify the best strategy for transferring TSV resistance from the TSV-R line to the Hybrid line, and the best strategy to ensure continued improvement in growth, pond survival, and TSV resistance. Two alternative approaches will be evaluated and the preferred strategy will be used to produce postlarvae to conduct on-farm trials at two commercial shrimp farms in the U.S., one in Texas and one in Hawaii. Located in the State of Hawaii, Kona Bay was founded in 1996 and is the worlds leading producer of specific pathogen free (SPF) and specific pathogen resistant (SPR) shrimp broodstock and disease-free clam seed.