Reproductive Cycles In Diaptomid Copepods: Effects of Temperature, Photocycle, and Species on Reproductive Potential

Abstract

Periodic changes in the oviducts of Diaptomus characterize a reproductive cycle in which females oscillate between gravid and nongravid conditions. The duration of the nongravid condition sets an upper limit for rates of clutch production. In laboratory studies of Diaptomus leptopus, D. pygmaeus, D. pallidus, and D. dorsalis, the cycle was unaffected by photoperiod but showed a strong temperature dependency. At a given temperature, the four species had a common cycle period but spent different amounts of time in the two phases of the cycle. Interspecific differences in the duration of the nongravid phase produced substantial variation in reproductive potential.