06/22/2005
Weird Jellies
Last night my wife and I attended our granddaughter’s last performance in a piano recital given by students of her teacher of many years. As usual, her piano teacher placed Dale last on the program, concluding with a rousing performance of a piece by Rachmaninoff. This fall, Dale is off to the University of Maryland to pursue her musical and liberal arts education. Until this morning, when I was led to the University’s medical school Web site, I hadn’t realized that Maryland is the site of the International Consortium for Jellyfish Stings. In fact, Dr. Joseph Burnett, in the Department of Dermatology, publishes the Jellyfish Sting Newsletter, the latest edition of which contains reference to two recent articles by one Jamie Seymour.
You may recall that last week I noted in passing that some unknown creature was stinging members of canoe clubs in Hawaii and that one suggested culprit was a tiny jellyfish. I knew jellyfish could be annoying, and sometimes deadly, but I didn’t realize how deadly until, after posting the column, I read the article “Killers in Paradise” by Paul Raffaele in the June Smithsonian magazine. Now I feel compelled, as a public service, to alert you swimmers and snorkelers to the box jellyfish. After reading the article, I would rather take my chances with a great white shark than with certain box jellies, which range in size from just a fraction of an inch to soccer or basketball size plus their trailing tentacles.
If you frequent the waters off the coast of Australia, especially in their summer, chances are you are very aware of box jellyfish. Just yesterday, down at Rutgers, I talked to my colleague, Tom, who had visited Australia this past winter, summer Down Under. While there, his wife snorkeled in the waters of the Great Barrier Reef near Cairns. Tom said they were informed about the jellyfish, which were indeed present. In fact, nets were installed out from shore to keep the jellyfish from the swimming areas. Tom’s wife wore a head-to-toe wet suit in case some of the little jellies made it through the nets. Raeffaele, in the Smithsonian article, began by saying that he had snorkeled at Opal Reef near Cairns and had not been told about Robert King, an Ohio resident, who had snorkeled there in April 2002.
Mr. King was stung by one of the smaller box jellyfish and, within less than half an hour, was suffering the “Irukandji syndrome”, with severe pain in his stomach, chest and back muscles. (The irukandji is one type of smaller box jellyfish but it seems that the term Irukandji syndrome is applied to the effects of stings by other members of the family as well.) In spite of being helicoptered to a Cairns hospital and heroic efforts to save King, he died two days later. A zoologist, the aforementioned Jamie Seymour, of James Cook University School of Tropical Biologyin Cairns, was called to King’s bedside to identify the source of the sting.
Seymour himself had been stung on the lip by an irukandji but survived – some species of irukandji are less toxic than the one that got King. The zoologist, Jamie Seymour, described his pain as between 15 and 20 on a scale of 1 to 10; yet he recovered in a day. Although only King’s death and perhaps one other have been traced to the irukandji, Seymour believes that many more have died from irukandji stings, drowning with symptoms resembling stroke or the bends.
Irukandji-like jellyfish are not confined to Australian waters but have been spotted off Guantanamo Bay and it is a good bet that swimmers in the Gulf of Mexico or in Hawaii have been stung by these small jellies. On my Marco Island walks, I often just missed stepping on large jellyfish washed up on the beach. I was under the impression that jellyfish just floated around or up and down with the currents, capturing food that randomly came within reach of their stinging tentacles. That seems to be the case with most jellies.
The box jellyfish are something else. They actually can chase their prey up and down or sideways, scooting along at speeds up to two or three miles an hour. And if you hear someone say there’s a sea wasp nearby, don’t think of a pesky insect. It’s another term for the most fearsome of box jellies, Chironex fleckeri, with a bell the size of your head and a plethora of tentacles, up to 180 yards of them. Each tentacle has billions of cells containing the most deadly venom known in Nature. Your chances of surviving a Chironex sting depend on how much tentacle latches on to you. If it’s less than four yards, you might survive, two if you’re a child. If the Chironex really latches on to you, you’ll be gone in a minute! There have been at least 68 recorded deaths caused by Chironex in Australia.
Because of their box-like shape, these jellies are also known as cubozoans. On each of the four sides of the box there’s a little black dot. Here’s where things begin to get weird. Each black dot consists of six eyes. In other jellies the eyes are just pits that detect the intensity of light from the given direction. In the box jellies, four of the eyes in each dot are pits; however, the other two eyes are more like our eyes, with a lens, cornea and retina. One of these human-like eyes points down, while the other points up! It appears that nobody really knows what these eyes “see”.
Presumably, all the signals from the 24 eyes get processed in the box jelly’s brain. Whoa, there’s a problem – the box jelly has 4 primitive brains! There’s a brain on each side, connected by the same link that connects to the eyes. Researchers have a real challenge trying to figure out how all these images are processed by 4 brains to come up with a command for the jelly to move in one direction or another.
With box jellyfish having multiple eyes and brains. Wouldn’t you also expect them to have multiple stomachs? You’re right, it does. Remember those 180 yards of tentacles in Chironex? The Chironex may have as many as 60 tentacles up to 3 yards in length; hence, the 180 yards. It turns out the stomach is in the tentacle – 60 tentacles, 60 stomachs! The food is processed in the bell into a partially digested soupy mix, which is funneled into the tentacle-stomachs for further digestion and absorption.
Seymour and his coworkers managed to tag some Chironex with transmitters. I’m not sure, no, I am sure that I would not want to try that job! They may have found that Chironex needs its naps. These jellies traveled around rather extensively, 210 meters an hour, in the hours between 6 AM and 3 PM. However, from 3 PM to 6 AM, the night shift, they only moved some 10 meters an hour. When Seymour, ever the adventurous type, dove down to see what was going on during the night shift, he was shocked to see the jellies resting motionless on the sea bottom with no usual pulsating of the bells. They seemed to be sleeping! Whether Chironex really sleeps or not is now a controversial topic.
Researchers are seeking antidotes for jelly stings and some progress is being made. We talked last week of barium sulfate in nets to cut down the unwanted catching of porpoises, dolphins and whales. Magnesium sulfate, a chemical cousin to barium sulfate, is showing some promise when a solution of it is injected into an irukandji victim’s veins. It seems to bring down the severe hypertension that results from a sting and also reduces the pain. For Chironex victims, an antivenin has been developed by inoculating sheep with Chironex venom. Of course, if you’ve been hit with too much more than 4 yards of tentacles, you’ll be dead before you get to shore!
Assuming that you don’t run into a Chironex, you might want to take some vinegar with you the next time you venture into a body of water. If a jelly stings you, vinegar kills those cells that remain on your skin but haven’t yet fired their venom. As for me, I shall continue to avoid immersing myself in water except in the shower.
Allen F. Bortrum
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