North Shore Sea Jellies Include the Colorful and Stinging Lion's Mane

Did you see any sea jellies over the summer? Sea jelly is the preferred word — for jellyfish — over at the New England Aquarium.

If you did see a sea jelly and it was white, most likely it was a moon jelly.

The Marblehead harbormaster told us in an earlier interview that he hasn't seen any jellies in recent years but there have been years where the white moon jellies were everywhere.

And Mike Armstong, assistant director for the Division of Marine Fisheries in Massachusetts, was once stung by a sea jelly in Marblehead Harbor.

That was back in the mid-1970s when he was a kid and jumping off docks.

The jelly was probably not a moonie. While moonies sting prey, they do not sting humans, typically, and even then their sting is very mild. 

The jelly that stung Mike was probably a lion's mane jelly, which is light-red in its bell and much bigger than a moonie, which have 6-8-inch tentacles.

Tony Lacasse of the New England Aquarium tells us lion's manes are a very nasty stinging jelly that is a regular part of the summer ecosystem along the eastern Massachusetts coast.

He had a couple colorful but true tales — let's call them tentacles — about lion's manes.

True Tentacle Number One took place on Seabrook Beach a couple summers ago.

A lifeguard thought to be doing a good deed by taking a pitch fork and pitching a big jelly from the beach into the water.

So much for good deeds. 

Lion's manes are loaded with stinging cells. 

When the lifeguard spiked the dead jelly with the pitchfork the jelly released its stinging cells. And within minutes people in the water had nasty stinging experiences.

Jelly Tentacle Number 2 is a bit of jelly trivia. 

Lion's mane venom was in a Sherlock Holmes mystery as the murder weapon. 

Not that a lion's mane sting would kill you by any stretch, but in the Holmes mystery the venom was highly concentrated.

Sea turtles like to eat the lion's manes, Tony said. So do sunfish.

Sea jellies are passive predators; they drift around.

They are longtime drifters, too.

They predate dinosaurs and even trilobites.

Sea jellies are 500 to 600 million years old, Tony says.