Stream‐dwelling copepods: Their life history and ecological significance1

The stream‐dwelling harpacticoid copepod Bryocamptus zschokkei was reared in the laboratory at 3.5°, 10°, 15°, 18°, and 20°C with naturally conditioned leaf disks as a food source. Egg and naupliar development rates were fastest at 18°C. A complete life table experiment was conducted at 18°C. Females were longer‐lived than other copepods and produced eggs continuously until death. The intrinsic rate of natural increase (r) and the net reproductive rate ( R o ) were found to be lower than those of most copepods. Reproduction is probably continuous throughout the year in the stream, since animals reproduced in the laboratory at the extreme temperatures experienced by the natural population. Since most copepods reproduce seasonally, the annual intrinsic rate of increase of B. zschokkei may be comparable to those of other copepods.