Lion’s Mane Jellyfish

As the lion is the king of terrestrial beasts, the lion’s mane jellyfish must be the king of the jellies. Named because its orange and gold bell and tentacles remind people of the color and texture of a lion’s mane, this animal can have a bell as much as 7 feet across and tentacles 100 feet long. Yet, it is made up almost entirely of water and has a short lifespan.

Five Incredible Lion’s Mane Jellyfish Facts

• Lion’s mane jellyfish found in the south are considerably smaller than those found in the far north.
• It can have as many as 1200 tentacles.
• Though its tentacles are full of stinging cells, many types of marine life hitch a ride on the lion’s mane jelly to be protected from predators and to share the jellyfish’s food.
• It makes up much of the diet of the leatherback sea turtle, which seems immune to its sting.
• Tentacles can sting even when they’re at a location far from the jellyfish, so beware.

Classification and Scientific Name

This jellyfish’s scientific name is Cyanea capillata. Cyanea comes from kuanós, the Greek word for “blue-green.” Others claim it is Latin for a pair of rocky islands. Capillata is Latin for “long hair,” which describes the jellyfish’s very long tentacles. Cyanea capillata is one of several species in the genus Cyanea.

Appearance

The lion’s mane jelly’s appearance is unmistakable. It can have a bell that’s nearly 7 feet across and trail tentacles that are over 100 feet long. Bearing eight lobes, the bell resembles a pattypan squash. Each lobe bears from 70 to 150 tentacles that are arranged in rows, and there’s a balance organ in the spaces in between them. This is called the rhopalium and lets the jellyfish tell up from down and right from left. There are also organs for odors and light perception. The location of the mouth is in the center of the lobes and contains the animal’s oral arms. These are frilled and full of nematocysts, or stinging cells, the jellyfish uses to stun its prey.

The bell and the orange arms are an orange or reddish color, much like the mane of a lion. They can also be shades of purple, pink, or violet. Despite all of this, the animal is at least 94 percent water.

Lion’s Mane Jellyfish vs Human: Just How Big Are We Talking?

Though there are photos that show a human being as a mere speck beside a grown lion’s mane jellyfish, the size difference isn’t that drastic. Most jellies have a bell that’s about 0.98 to 2.62 feet in diameter with 6 to 8-foot-long tentacles.

Distribution, Population, and Habitat

The jellyfish are found in the colder parts of the Atlantic and Pacific Oceans. Other locations are in the Baltic and the North Sea. Some are found off the coast of Australia. They are rarely found in water deeper than 66 feet.

Predators and Prey

Grown lion’s mane jellyfish are too big and venomous for predators to tackle, but the much smaller juveniles are just the thing for sea birds, sea anemones, larger jellyfish, sea turtles, and big fish such as molas. As for their prey, the adult jellyfish eat a great variety of marine animals. These include the nearly microscopic animals that make up the zooplankton, shrimp and other small crustaceans, small fish, and moon jellyfish.

The jellyfish hunts by lowering itself upon its prey, then paralyzing it with the stinging cells in its tentacles. How the jellyfish eats after it’s caught its prey is complicated and requires the motion of the tentacles transferring the prey to the jelly’s oral arm, which then passes it to the manubrium, which is like an esophagus, then to the stomach. If the prey is too large for the stomach, the jellyfish uses its oral arms to start digesting it.

Reproduction and Lifespan

As with all jellyfish, this jellyfish’s reproductive strategy is even more complicated than its digestive strategy. Though some biologists believe the animal is asexual, there are indeed male and female lion’s mane jellyfish, as one produces sperm and the other eggs. But its reproduction is both sexual and asexual.

First, the jellyfish ejects sperm and eggs from the mouth. When they are fertilized, they are incubated in the oral tentacles of the female for about a day. This is how long it takes for them to hatch into planula larvae. The female then removes them to a firm surface where they develop further into tiny plantlike creatures called polyps. These polyps reproduce asexually by producing columns of discs called ephyrae. These ephyrae then break out of the columns and grow into medusae, which are basically tiny jellyfish. These medusae grow until they too are ready to reproduce sexually. Though the rule of thumb is that the larger an animal is, the longer it lives, the lifespan of this huge jellyfish is about a year or even less.

Population

Though biologists don’t have precise numbers of this jellyfish, its population is robust enough to sustain the population of the leatherback turtle. Lion’s mane jellies are just about all the turtle eats. The IUCN hasn’t evaluated the jellyfish, but it is not in danger of extinction.