Jellyfish system. Nematocysts, which deliver the sting, are located mostly on the tentacles; true jellyfish also have them around the mouth and stomach. Jellyfish do not need a respiratory system because sufficient oxygen diffuses through the epidermis. They have limited control over their movement, but can navigate with the pulsations of the bell-like body; some species are active swimmers most of the time, while others largely drift. The rhopalia contain rudimentary sense organs which are able to detect light, water-borne vibrations, odour and orientation. A loose network of nerves called a "nerve net" is located in the epidermis. Although traditionally thought
Jellyfish jellyfish, "Stomolophus meleagris", along the southern Atlantic coast of the United States and in the Gulf of Mexico for export to Asia. Jellyfish are also harvested for their collagen, which is being investigated for use in a variety of applications including the treatment of rheumatoid arthritis. Aristotle stated in the "Parts of Animals" IV, 6 that jellyfish (sea-nettles) were eaten in winter time in a fish stew. In some countries, such as China, Japan, and Korea, jellyfish are a delicacy. The jellyfish is dried to prevent spoiling. Only some 12 species of scyphozoan jellyfish belonging to the order Rhizostomeae are