Text and Photo by Peter Vankevich
Two years ago or so, I featured in this column the Cannonball Jellyfish (Stomolophus meleagris) that had been spotted just off the beach at Springer’s Point. I noted that unlike many jellyfish, their toxins are relatively harmless to humans with little stinging capabilities. This month’s feature, another jellyfish (or these days also called “sea jellies”), goes by the curious name of Lion’s Mane (Cyanea capillata) and deserves a little more attention in how it is approached as was illustrated in a rather bizarre beach incident that occurred up north earlier in the summer.
This species gets its name from its very long tentacles that some thought looks like the mane of a lion. It is particularly noteworthy for being not only the world’s largest jellyfish but capable of growing into one of the longest animals in the world, one specimen caught back in 1870 measured 120 feet, longer than a Blue Whale! The large crown, called the bell, can range from a diameter as little as five inches up to nearly seven feet. They are normally denizens of the northern cold waters of the Atlantic, Pacific and Arctic Oceans. On the Atlantic side, most of the year they rarely venture below the 42nd parallel, i.e. around Cape Cod. They will drift onto the Outer Banks, however, when the waters cool in late fall and winter so it was a bit of a surprise to me to see this one beached near the Ocracoke/Hatteras ferry terminal on June 6, 2010.
Lion’s Mane feed primarily on zooplankton, small fish, ctenophores (when pronounced the c is silent), and moon jellies. On the other side of this food chain, its predators include seabirds, large fish and sea turtles. It is a member of the phylum Cnidaria (pronounced nigh-daria, another silent c). A notorious trait of Cnidaria is that they have microscopic structures known as nematocysts located along their tentacles which inject toxins into their prey. Nematocysts will cause variable degrees of stinging sensations when they come in contact with human skin which is a good reason to avoid touching them.
This species made quite a splash in the news earlier in the summer when it was reported that up to 150 people were stung by a large jellyfish on a popular beach in New Hampshire within a period of about one half hour.
So what happened? According to several news reports, a very large jellyfish weighing up to fifty pounds with tentacles as long as 12 feet was spotted in the water among many swimmers. Lifeguards attempted to pull it to shore with a pitchfork resulting in breaking the tentacles into many pieces that ended up both in the water and on the beach.
People soon began complaining of itchiness and a stinging sensation. There was so much commotion that five ambulances and a hook and ladder truck showed up, and according to one report, the lifeguards were sent to local stores to purchase the recommended antidotes baking soda and vinegar. No one was seriously injured, but a few children were sent to the hospital as a precautionary measure and released.
So what can be done if one encounters a Lion’s Mane on Ocracoke? Well the preferred method of removal would not be by pitchfork amidst a bunch of swimmers – an extremely unlikely event on Ocracoke. In fact, they are best left alone. If one is seen on the beach, avoid walking barefoot in the area since there may be pieces of hard to see tentacles around. They may still produce stings up to three or four days after breaking off.
If seen in water while swimming, move away from that immediate area. The sting of a Lion’s mane is not considered dangerous, but common sense dictates, like a bee sting, if one encounters symptoms that are severe such as dizziness or respiratory distress after coming into contact with one, the person should seek medical attention immediately.
This sea jelly enjoys a bit of literary fame thanks to one of Sir Arthur Conan Doyle’s Sherlock Holmes writings called The Adventures of the Lion’s Mane. This is one of the few stories narrated by Holmes himself rather than by Dr. Watson. (Doc. Watson is a much better story teller.) Holmes observes a man running from the beach in apparent distress mutters the phrase “Lion’s Mane” and drops dead.
The rest of the story involves eliminating suspects and concluding that that the killer was the jellyfish. Early on it was observed that the victim had a heart condition that saved Doyle from taking much more than a tad of poetic license.
Categories: Ocracoke nature, flora & fauna