Regulation of Cyanea capillata populations by predation on their planulae

Abstract

A series of feeding trials was carried out, offering planula larvae of Cyanea capillata to three potential predators, Mnemiopsis leidyi, Mytilus edulis and Ciona intestinalis, alone or mixed with algae or copepods. Mussels and ascidians consumed planulae in significant numbers in all prey combination trials, whereas ctenophores did so only when planulae were offered as sole prey. These results suggest that grazing pressure on scyphozoan planulae may play an important role in regulating medusa blooms.