MARCACCIO, N.D.; SPECKER, J.L.; University of Rhode Island, Graduate School of Oceanography; University of Rhode Island, Graduate School of Oceanography: Stress in Summer Flounder: Anesthesia Mitigates Transportation-Induced Stress Response and Increases Post-Transport Performance

A significant problem affecting the mariculture of summer flounder Paralichthys dentatus, is the incidence of post-transport epizootic, leading to significant delayed mortality. We hypothesized that transportation-induced stress was the indirect cause of these incidents and could be mitigated through the use of anesthetics, leading to improved performance. Our research confirmed that transportation causes a significant stress response in this species. Indicators included elevated plasma cortisol and glucose levels as well as disruptions in plasma ion concentrations. The anesthetics MS-222 (tricaine), 2-PE (2-phenoxyethanol), eugenol, and metomidate were evaluated for their capacity to prevent changes in these parameters during transportation. Proper doses of anesthetics were determined for the partial sedation required during high-density transport. One and four hour transports were conducted to test the effects of each anesthetic on the stress response. Only MS-222 and metomidate were shown to prevent or ameliorate changes in key stress parameters. A 24 h post-transport salinity tolerance test (STT) was utilized to test performance after four-hour transports under MS-222 and metomidate sedation. Only metomidate was shown to increase post-transport performance in the STT. There is a strong link between the ability of metomidate to limit the stress response and an increased post-transport performance capacity in summer flounder. [Research supported by NOAA/NMFS Saltonstall-Kennedy (U.S. Department of Commerce)]