Superfluous Feeding and Growth of Jellyfish Aurelia aurita

Abstract

According to a recently presented bioenergetic model for the weight-specific growth rate of jellyfish, Aurelia aurita, fed brine shrimp, Artemia salina, the specific growth will remain high and constant at prey concentrations > 6 Artemia l−1. The aim of the present study was to verify this statement by conducting controlled feeding and growth experiments on small jellyfish in tanks. It was found that prey organisms offered in concentrations of 25, 50, and 100 Artemia l−1 resulted in specific growth rates in fair agreement with the model-predicted rates. The high prey concentrations resulted in superfluous feeding and production of pseudofeces which indicated that not all captured prey organisms were ingested but instead entangled in mucus and dropped. The high prey concentrations did not influence the filtration rate of the jellyfish.