A comparison of physiological changes in carp, Cyprinus carpio, induced by several pollutants at sublethal concentration--II. The dependency on the temperature.

Carp were exposed to 10 different pollutants with sublethal concentrations at 12, 17 or 22 degrees C. The effects on the serum cortisol and glucose levels, the amount of liver and muscle glycogen and the concentration of protein and cholesterol in the serum were examined. The level of serum cortisol and glucose increased, the amount of liver and muscle glycogen decreased and the protein and cholesterol concentration were reduced after exposure to the pollutants. The cortisol and glucose response was similar at all temperatures, slightly reduced at 17 degrees C. The glycogen reaction was strongest at 17 degrees C and the protein and cholesterol response was low at 12 degrees C and increased with the temperature. The explanation of the different temperature dependency is difficult. Carp are stressed and have low metabolic rate at 12 degrees C. They have good conditions at 17 degrees C and have a higher energy demand at 22 degrees C. These simple differences cannot exactly explain the different dependency.