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Associate Professor

Ph.D. - North Carolina State University, 1983

Phone: 301-405-7974
Email: curry@umd.edu

Resarch Interest:

Stress is unavoidable in the aquaculture environment. Exposure of fish to common laboratory and hatchery stressors such as handling and net confinement activates the hypothalamus-pituitary-interrenal axis and leads to increases in circulating levels of adrenocorticotropic hormone, cortisol and glucose and decreases in plasma levels of chloride. Although these responses are generally considered adaptive, repeated or prolonged exposure to stress can depress growth rate, and increase the incidence of disease directly though the immunosuppressive effects of cortisol. Acute and chronic stress can also alter reproductive function by reducing production of gonadal steroids (i.e. testosterone or estradiol), which have been shown to decrease: gonad size, gamete quality, and progeny survival.

Continued expansion of the hybrid striped bass aquaculture industry is hindered in part by the inability to capture necessary numbers of mature broodstock to supply culturists seed stock in adequate quantity throughout the year. Presently mature animals must be collected from the wild during the spawning season, hormonally induced to undergo final maturation and then stripped of their gametes for in vitro fertilization. Since the capture and spawning of wild broodstock is stressful and often results in high morbidity and mortality, significant interest is growing to develop domesticated stocks, which can be genetically improved for superior performance characteristics. It is unclear, however, whether modification of the stress response is of any significance to the fish other than during a stressful condition or whether selection for stress responsiveness inadvertently co-selects any undesirable traits.

My laboratory is currently evaluating the reproductive performance of high stress responsive (HR) and low stress responsive (LR) male striped bass during typical hatchery operation procedures. Previously identified HR and LR male striped bass will be periodically stripped of their milt. Sperm quality will be assessed and blood samples will be analyzed for gonadal steroids and cortisol. To determine whether cortisol can be implicated in depressed gonadal steroid levels, HR and LR males will be implanted with cortisol and their blood analyzed for gonadal steroids. These experiments will help determine whether striped bass selected for the stress responsiveness trait provide any practical benefit in terms of reproductive performance. In addition, results from my lab’s studies will identify differences between the reproductive performance of HR and LR male striped bass during simulated hatchery spawning operations. Our results will have immediate practical application to the industry since: 1) striped bass males are used to commercially produce the reciprocal hybrid, or “Sunshine Bass”; and 2) we will be able to correlate handling of striped bass males to reproductive efficacy. We anticipate that our results will identify stress-tolerant individuals with superior reproductive performance that will lead to the development of striped bass lines well suited for intensive aquaculture conditions. In addition, by developing a better understanding of the interaction between stress and reproduction, more informed decisions regarding the timing of non-avoidable stressful procedures may lead to increased reproductive efficiency, improved gamete quality for in vitro fertilization or cryopreservation, and animal well-being.

Third generation domestic male striped bass.

Representative Awards and Honors

- Received Gamma Beta Phi Fellowship Award, 1971, Murray State University.
- Inducted into Phi Kappa Phi National Honor Society, 1981, North Carolina State University.
- Certified (1986) as a Fisheries Scientist by the American Fisheries Society’s Board of Professional Certification. Re-certified in 2001.
- Appointed (1992) Lead Scientist for the University of Maryland Aquaculture Advisory Delegation to post-USSR Russia.
- Received Postdoctoral Fellowship Award, 1995, Office of Economic and Cooperative Development