Monitoring of swarming by Scyhomedusae

Abstract

Conference on jelly-fish blooms in the Mediterranean. The jelly-fish proper (scyphomedusa) is the dominant, sexual free-swimming life stage of the scyphozoans. As compared with the hydrozoan medusa, it is usually larger and more conspicuous, with a well developed umbrella margin which is divided into lappets, carrying tentacles and sensory organs but possessing no velum. The scyphomedusae are the most conspicuous planktonic forms, often occurring in large swarms extending over large areas and thus becoming a nuisance due to the possible clogging of fishing nets and the stinging of bathers. Moreover, at least in certain areas, they constitute a major component of the epipelagic ecosystem.