Thermal resistance, preferred and avoidance temperatures of Cyclops strenuus Fischer, 1851, and their relation to optimal, pessimal, and tolerant temperatures

Abstract

Ranges of preferred and avoidance temperatures in Cyclops strenuus Fischer, 1851 were determined based on the results of its experimental testing in the thermal gradient device. It is established that the process of temperature selection occurs with an overshoot. It is noted that copepods started to select the final preferred temperatures on the 8th day (temperatures above 26°C were avoided; the avoidance of low temperatures was not recorded). The average value of the critical thermal maximum for the season was determined. It is found that optimal, pessimal, and tolerant temperatures can be calculated on the scale of the species tolerance according to values of preferred and avoidance temperatures as well as according to values of the temperature range of regulation of the critical thermal maximum.