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Ocean
Watch
Monday, March 26, 2001
Sea anemones pack
a big sting in a small
and delicate body
Last week a fifth-grader e-mailed me asking about
anemones. Since I couldn't remember much about the subject, I looked in my
anemone file for information. An article there brought back some fond
memories.
A few years ago, a mainland medical student stayed with
us for six weeks while she studied emergency medicine. Almost immediately,
Maggie began pursuing her dream of learning to scuba dive. She enrolled in
a class, studied her lessons and drove around the island researching
different types of gear.
Finally she was ready for her open-water certification
dive. She packed her new equipment, and off she went to meet her
instructor and classmates on the Waianae Coast.
Later that afternoon, she walked into the kitchen
looking miserable.
"Are you OK?" I asked.
Maggie turned to show me her right calf. A red, raised
hive about 6 inches in diameter covered her leg. At its center rose five
or six big blisters, some intact, some draining clear fluid down her leg.
The whole area was raw and painful.
"What happened?" I asked.
"I don't know. I was swimming along and my leg
brushed a rock. It was so slight I barely felt it. What could have made
such a bad sting?"
I had no idea. I called my husband, an emergency
doctor, and told him the story. "What should we do?" I asked.
"Take a picture of it," he said.
"No, seriously."
"I am serious," he said. "I don't know
what stung her either, but whatever it is, there's no cure. Get a
picture."
Maggie accepted this verdict, and we all went back to
work.
Months later, I was reading a journal article about a
marine animal in the Red Sea that causes severe stings. The description of
the injury sounded familiar: "Usually, a hive appears encircled by a
red halo. ... In severe cases, blisters and skin ulcers may occur."
Maggie experienced some other listed symptoms, too, such as swollen lymph
glands.
I looked up the species and, to my surprise, discovered
that a tiny version of the same animal is found in Hawaii. The culprit,
which we believe stung our guest, is a lovely little sea anemone.
Sea anemones (an-NEM-on-ees) are relatives of
jellyfish, Portuguese men-of-war and corals. Each anemone is a single
animal with a soft, vaselike body topped with short tentacles, like a
bouquet of fleshy flowers. Beneath the tentacles is the creature's mouth.
Anemones are meat eaters, feeding on drifting animals
and sometimes fish. After stinging its prey, the anemone transfers the
paralyzed creature to its mouth, where the anemone swallows it whole.
At least 20 kinds of anemones live in Hawaii. Some
spend their entire lives in one place; others move around. One little crab
in Hawaii carries an anemone (Triactis producta, the one that probably
stung Maggie) in each claw for defense. Other anemones live on the shells
of hermit crabs.
Hawaii's anemones are small and scarce compared to
those in some tropical areas. For instance, in the Red Sea, Triactis
producta is 3 inches tall and 1 1/2 inches wide. In Hawaii the same animal
is 1/2 inch by 1/2 inch. Stings are not common here but, as we learned in
Maggie's case, they can be severe.
People usually compare an anemone sting to a bee sting,
but reactions vary according to the person and the species. There is still
no specific treatment for anemone stings except to wash the area, then try
ice packs for pain.
Maggie, by the way, passed her open-water dive test
that day. And we have some great pictures of her sting.
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