The reproductive potential of two harpacticoid copepods, Tachidius discipes and Paronychocamptus nanus, as measured by the intrinsic rate of natural increase, rm, has been studied. The influence of temperature on all factors used in the calculation of rm has been taken into account. Generation time, which has also been detected in a third species, Nitocra typica, is the single factor which is most affected by temperature and which has the most pronounced effect on rm. Values of the reproductive potential differ considerably according to temperature, and thus to the time of the year; during the spring bloom more than half the reproductive potential is realized. |