Few marine creatures are as Both stationary and mobile Jellyfish exist in many sizes, mysterious and intimidating members of this group have radial shapes and colors. Most are as jellyfish. Though easily symmetry with body parts radiating somewhat transparent or glassy, recognized, these animals are from a central axis. This allows with a bell shape. The bell may be often misunderstood and feared jellyfish to detect and respond to less than an inch across or more by beach goers, even though most food or danger from any direction. than a foot across. A few species jellyfish in South Carolina waters Jellyfish have an outer layer reach seven feet in diameter. are harmless. This publication which covers the external body The tentacles of some jellyfish will help coastal residents and surface, and an inner layer which grow to more than 100 feet long. vacationers learn which jellyfish to lines the gut. In between is a layer Regardless of their size or shape, avoid, and the ones you can safely of thick elastic jellylike substance most jellyfish are very fragile, ignore. called mesoglea or middle jelly. consisting mostly of water. Jellyfish belong to a large group Jellyfish have a simple digestive Jellyfish inhabit all the world’s of marine animals that include cavity with four to eight oral arms oceans and can withstand a attaching organisms such as sea near the mouth. These arms wide range of temperatures and anemones, sea whips, corals transport food captured by the salinities. Most live in shallow and hydroids that grow attached tentacles into the mouth. coastal waters, but a few inhabit to rocks or other hard surfaces. Lacking a brain, jellyfish instead depths of 12,000 feet. Jellyfish and their relatives such have a elementary nerve net as the Portuguese man-of-war are capable of detecting light, odor mobile, either actively swimming and other stimuli and coordinating or pushed by winds and currents. the animal’s responses. GENERAL MEDUSA BODY PLAN mouth tentacles oral arm gonad bell stomach JELLYFISH LIFE CYCLE medusa planula larva ephyra budding polyp polyp Life Cycles or in brood pouches along the oral ocean currents, tides and wind. Jellyfish have alternate arms. generations in which the animal Eventually, small swimming Food passes through two different body larvae leave the female and enter Jellyfish form an important forms. They begin life as small the water column. After several part of the marine food web. polyps attached to solid surfaces days they attach themselves to Carnivorous, they feed on a variety such as rocks or shells. Using something firm on the sea floor of small floating organisms as well their tentacles, polyps feed on gradually transforming into flower- as comb jellies and occasionally microscopic organisms in the like polyps to start the life cycle other jellyfish. Larger jellyfish water. Polyps can multiply by over again. Jellyfish medusae can capture and devour large producing buds or cysts that normally live for a few months; crustaceans and other marine separate from the first polyp and however, the polyp stage may organisms. develop into new polyps. survive for years. In turn, many marine animals, When fully developed, polyps including spadefish, sunfish, and constrict in their bodies, eventually Locomotion sea turtles eat jellyfish. Some producing larvae which resemble Adult jellyfish drift in the species, including the mushroom a stack of saucers. Each individual water with limited control over and cannonball jellyfish, are saucer develops into a tiny jellyfish horizontal movement. However, considered a delicacy by humans. which separates itself from the muscles that contract the bell, Pickled or semi-dried mushroom stack and becomes free swimming. reducing the space under it, force jellyfish are consumed in large In a few weeks, they grow into an water out through the opening quantities in Asia, where they adult jellyfish, called a medusa. with pulsating rhythm that creates constitute a multimillion-dollar part The dominant and conspicuous vertical movement. of the seafood business. medusa are either male or female. Some jellyfish, such as the The reproductive organs (gonads) sea wasp, descend to deeper Venom Apparatus develop in the lining of the gut. waters during the bright sun of For defense and feeding jellyfish During reproduction the male the midday and surface during have specialized stinging cells releases sperm into the water early morning, late afternoon and which contain venom. The and the swimming sperm are evening. For horizontal movement stinging structure consists of a swept into the female. Embryos from place to place however, hollow coiled thread with barbs develop either inside the female jellyfish largely depend upon along its length. These nematocysts NEMATOCYST BEFORE DISCHARGE JELLYFISH LIFE CYCLE of stings from jellyfish occur in cnidoblast tropical and warm waters. Most hollow jellyfish along the South Carolina nematocyst thread coast inflict only mild stings that result in minor discomfort. Local Jellyfish Although most jellyfish that major barb inhabit South Carolina waters are trigger harmless to humans, there are a few that require caution. Learning how to identify the different NEMATOCYST AFTER DISCHARGE species can help you decide which Lion’s MANE cnidoblast ones can be safely ignored. Lion’s Mane (Cyanea capillata) nematocyst Also known as the winter jelly, the lion’s mane typically appears during colder months. The bell, measuring 6-8 inches, is saucer-shaped with reddish-brown oral arms and eight clusters of tentacles hanging trigger underneath. Stinging symptoms are similar to those of the moon jelly major barb but, usually more intense. Pain is relatively mild and often described CANNONBALL JELLY as burning rather than stinging. are concentrated on the tentacles Cannonball Jelly Mushroom Jelly or oral arms. A single tentacle (Stomolophus meleagris) (Rhopilema verrilli) can have hundreds or thousands (Also known as the jellyball, and The mushroom jelly resembles of nematocysts embedded in the the cabbage head jelly) the cannonball jelly, but differs in epidermis. Cannonball jellyfish are the most many ways. The larger mushroom When tentacles make contact common jellyfish in our area, jelly, growing 10-20 inches in with an object, pressure within and fortunately, one of the least diameter, lacks the brown band of the nematocyst forces the stinging venomous. During the summer the cannonball and is much flatter thread to rapidly uncoil. The and fall, large numbers of this and softer. Like the cannonball, the thousands of nematocysts act as species appear near the coast mushroom jelly has no tentacles small harpoons, firing into prey and in the mouths of estuaries. and a chunky feeding apparatus, and injecting paralyzing toxins. Cannonball jellies have round but differs in its long fingerlike Jellyfish use stings to paralyze white bells bordered below by a appendages that hang from the or kill small fish and crustaceans, brown or purple band. They have feeding apparatus. but the stings of some jellyfish can no tentacles, but they do have a This species is also considered a harm humans. Jellyfish do not firm, chunky feeding apparatus pest by commercial fishermen, but “attack” humans, but swimmers formed by the joining of the oral they are much less of a problem and beachcombers can be stung arms. than cannonball jellies. The when they accidently touch Cannonballs rarely grow larger mushroom jelly does not represent jellyfish tentacles. than 8-10 inches in diameter. a hazard to humans. The severity of the sting depends Commercial trawl fishermen on the species of jellyfish, consider them pests because they the penetrating power of the clog and damage nets, and slow nematocyst, the thickness of the down fishing. victim’s skin, the sensitivity of the victim to the venom. The majority bell and can extend several feet. extremely painful stings. Symptoms Considered moderate to severe, include severe shooting pain sea nettle stings are similar to described as a shock-like sensation, those of the lion’s mane. This and intense joint and muscle species causes most of the jellyfish pain. Pain may be accompanied stings that occur in South Carolina by headaches, shock, collapse, waters. Exercise caution if sea faintness, hysteria, chills, fever, nettles are observed in the water, nausea and vomiting. and do not swim if large numbers Initial contact with a man-of-war are present. may produce only a small number MOON JELLY of stings. But trying to escape from Sea Wasp the tentacles may greatly increase (Chiropsalmus quadrumanus) stings. Severe stings can occur Southern Moon Jelly Known as the box jelly because even when the animal is beached (Aurelia marginalis) of its cube-shaped bell, the sea or dead. Probably the most widely wasp is the most venomous Another jellyfish, the smaller recognized jellyfish, the moon jellyfish inhabiting our waters. by-the-wind-sailor, also has a blue jelly occurs infrequently in Their potent sting can cause bladder and occasionally enters South Carolina waters. It has a severe skin irritation and may South Carolina coastal waters, but transparent, saucer-shaped bell require hospitalization. Sea wasps causes only a mild, tingling sting. and is easily identified by the four are strong, graceful swimmers Given the significant danger of the pink “horseshoes” visible through reaching 5-6 inches in diameter man-of-war, all jellyfish having a the bell. It typically reaches 6-8 and 4-6 inches in height. Several blue float should be considered inches in diameter, but some long tentacles hang from the four dangerous. exceed 20 inches. corners of the cube. A similar The moon jelly is only slightly species, the four-tentacled Tamoya venomous. Contact can produce haplonema, also occurs in our prickly sensations to mild burning. waters. Pain is usually restricted to immediate area of contact. Portuguese Man-of-War (Physalia physalis) Although closely related to jellyfish, the Portuguese man-of- war is not a “true” jellyfish.