Jellyfish
Although most jellyfish live well off the ocean floor and form part of the plankton, a few species are closely associated with the bottom for much of their lives and can be considered benthic. The upside-down jellyfish in the genus "Cassiopea" typically lie on the bottom of shallow lagoons where they sometimes pulsate gently with their umbrella top facing down. The tiny creeping jellyfish "Staurocladia" and "Eleutheria" cannot swim, and "walk" around on seaweed fronds or rocky bottoms on their tentacles. Most hydromedusae and scyphomedusae that live in coastal habitats find themselves on the bottom periodically, where they may stop swimming for a while, and certain box jellyfish species also rest on the sea bed in shallow water. Even some deep-sea species of hydromedusae and scyphomedusae are usually collected on or near the bottom. All of the stauromedusae are found attached to either seaweed or rocky or other firm material on the bottom.
Jellyfish as food
In 2001, the annual global harvest of edible jellyfish was estimated to be around 321,000 metric tons. The most prominent countries involved in edible jellyfish production are Burma, China, Indonesia, Korea, Malaysia, the Philippines and Thailand. In China, jellyfish larvae are reared in ponds before being released as juveniles into the sea to grow and mature. In Southeast Asia, edible species of jellyfish may be harvested using various nets such as drift nets, scoop nets, set nets and hand nets, hooks and beach seines. In 2001, the estimated annual catch in Southeast Asia in net weight was at around 169,000 metric tons. The amount of jellyfish caught annually in this region can vary significantly, and the fishing season for them is relatively short, at two to four months.