Fingerling American Shad: Effect of Valium, MS-222, and Sodium Chloride on Handling Mortality

Abstract

Two experiments were conducted to study the effects of Valium, MS-222, and sodium chloride on the mortality induced by handling and transporting fingerling American shad (Alosa sapidissima). Fish that were given an oral administration of Valium (0.04 mg/kg fish) and transferred without removal from the water (water transfer), showed nearly 100% survival for 24 h in a polyethylene bag without any delayed mortality. The removal offish from the water (air transfer) during handling resulted in heavy scale losses. Oral administration of Valium (0.08 mg/kg fish) did not prevent high mortality (more than 80%) when scale losses were excessive. Addition of sodium chloride to the transporting water (1%) showed a significant beneficial effect on survival for up to 4 h; however, it was not effective in preventing mortality caused by severe scale losses. MS-222 at a concentration of only 10 mg/L proved to be toxic to shad. The results of these experiments suggest that fingerling American shad can be successfully transported in a polyethylene bag with 1% sodium chloride if hyperactivity during handling is controlled by oral administration of Valium (0.04 mg/kg fish), and if physical damage is minimized through water transfer.