Simmons, H.B.2010-02-152010-02-151971http://hdl.handle.net/1969.3/2040142 p., ThesisCyprinodon variegatus collected in November 1969 on Galveston Island, Texas at 19.2 C and 2.7 o/oo salinity were acclimated at 30 C and 1, 10, 20, and 30 o/oo salinity and subjected to heat death at 40.8 and 41.4 C at their acclimation salinity. Samples were killed daily for 26, 29-30, 21 and 11 days respectively at 1, 10, 20, and 30 o/oo. At the end of the experiment, survival times of fish being acclimated at 1, 20, and 30 o/oo were still increasing. These results are at variance with the assumption, usually used in high temperature experiments with fishes, that acclimation is complete in 3 days. At 10 o/oo the highest level of acclimation recorded was attained within 14 and 15 days at a kill temperature of 41.4 and 40.8 C respectively. Fish were the most resistant to heat at 10 and 20 and the least at 1 and 30 o/oo. Survival times fluctuated among days. Sex and length were a factor in survival time only at 1 o/oo salinity (sex only at 40.8 C). Long and male fish had the longest survival times.marine fishsheepshead minnowCyprinodon variegatustemperature toleranceacclimationThermal resistance and acclimation at various salinities in the sheepshead minnow (Cyprinodon variegatus Lacepede).Book