Jellyfish are not fish by definition and are often called jellies for that reason. They are plankton – just typically on the larger end of the plankton range. Plankton is Greek for “drifter,” which means free-floating organisms that can’t move themselves from place to place. But then we saw a jelly pulsing on the beach and re-thought the whole “not moving” definition.

I watched the fine striping on its gelatinous surface, the lines squeezing together and then relaxing, and wondered if this jelly was not doing so well. There was a sloppy mess of jelly body strewn across the middle of the mass lying on the rocks that made me think I was looking into its insides. But, after looking for awhile, the colors of its body provided an overlooked clue. The dark red of the bell was hard to see against the grey rocks at first, but then I realized it was upside down. What we were seeing was a rare peek into the underside of the animal – one that is more typically seen from the top when washed ashore, its tentacles tucked underneath. It was amazing to see the strong motions of this supposed drifter out of water. We gently turned it over ahead of the incoming tide and, sure enough, it was gone the next time we looked.

The jelly we were looking at was a lion’s mane (Cyanea capillata), named because it has a reddish bell and long flowing tentacles akin to a mane of a male lion. Its Latin Genus name is a bit misleading since cyanea means blue and the lion’s mane is red, but its nearest relative is the Blue Jelly. Capillata, Latin for long-haired, is more appropriate. Lion’s mane jellies are one of two commonly seen jellies near shore in Maine. The other is the moon jelly, which looks quite different because it is completely white or clear. These are cold water jellies and are found in the Arctic and northern Pacific as well as the northern Atlantic. The other major difference is that the stinging cells of a moon jelly are not very potent and cause little or no irritation if a tentacle brushes up against your skin.

Lion’s manes, on the other hand, can sting if you touch their tentacles. Their sting is not often serious, but can make your skin tingle and get red. The exception is if you happen upon one of the bigger individuals. And, they can get impressively big! The record largest lion’s mane measured seven feet across with tentacles that were 120 feet long. That’s longer than a blue whale, challenging its status as the biggest in the world.

While the tentacles of the one we saw on the beach were all scrunched up, when they are flowing in the water, you can see that there are hundreds of them. Rows and rows of them dangle from each of the jelly’s eight lobes that make up the umbrella-shaped bell. The longest ones are the prettiest and can look frilly and feathery. There are four of them surrounding the mouth and these have particularly strong stinging cells. If you see one upside-down, these long tentacles look like a plus sign. The smaller individuals, like the one we saw, eat tiny plankton, larger ones can use their tentacles to capture fish and other jellies and move them into their mouth underneath.

Lion’s manes can be fearsome predators, but they can also be safe havens for fish that are protected by a coating on their skin from their sting – much like Nemo hiding in an anemone. It’s a way for them to have a little community as they are usually found drifting solo out in the open ocean where they spend most of their lives. They’re often found close to the coast in the spring when there is a big crop of plankton, which is why we are finding them now.

You might wonder what eats these large gooey creatures. They aren’t the easiest to grip onto, but sometimes are eaten by seabirds, bigger fish, and sea turtles. Their sting protects them to some degree, but the impact of the sting is really on exposed skin and turtles don’t have much. The bit of skin they have that isn’t under a shell is protected by scales. The same is true for some fish and for sea birds that have feathered protection.

You might not want to seek protection under a jelly, but I’ve always wanted to see one out in the ocean with little fish hanging out underneath. Despite the pulsing we saw, jellies don’t move too quickly. So, you don’t need to worry about being chased by one. Just keep an eye out for them while swimming. They are fairly easy to spot with their dark color and are usually up at the surface. And, once the water warms up a bit more, you don’t have to worry at all, as they will have moved back out to sea.

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