The lion’s mane jellyfish is the world’s largest jellyfish, so it’s daunting to come across as a diver or swimmer, despite being relatively harmless to humans.
Lion’s mane jellyfish are vibrantly colorful, exhibiting reds and yellows. They are also bioluminescent to lure prey.
What Is The Lion’s Mane Jellyfish?
The lion’s mane jellyfish is the largest jellyfish in the world with tentacles that can grow to over 100 ft (30.5 m) long. Their bells can grow up to 8 ft (2.4 m) in length, and their bodies can reach up to 200 lbs (90.7 kg).
Some lion’s mane jellyfish grow large enough to rival blue whales. Blue whales are the largest animal in the world, typically growing to about 90 ft (27.4 m) in length.
The largest known lion’s mane jellyfish was 120 ft (36.6 m) long.
Vibrantly Colorful
Besides being the largest jellyfish in the world, the lion’s mane jellyfish is also one of the most colorful. Its bell is dark yellow or red, with the deepest coloration near the top. The top of the bell is also the thickest area of the animal’s body. Its body mass thins near the edges of the bell where the tentacles attach.
Smaller jellyfish with bells less than 5 in (12.7 cm) are often more colorful, being yellow or pink. Lion’s manes between 5-18 in (12.7-45.7 cm) are a darker red or yellowish-brown. Large jellyfish with bells over 18 in (45.7 cm) are usually a dark brownish-red. The oral arms that lion’s manes use to eat are typically purple.
This jellyfish with long tentacles also possesses bioluminescent abilities, meaning that it can glow.
Many Tentacles
Eight indentations, called lobes, divide the bell. Some of these lobes contain sensory organs that help with balance and allow the jellyfish to sense smell and light.
Its long, flowing tentacles earned the animal its name. The bell divides the tentacles by eight sections, with 150 tentacles in each section. Overall, a lion’s mane jellyfish has about 1,200 tentacles.
Like all true jellyfish, the lion’s mane jellyfish has nematocysts within its tentacles. Nematocysts are special cells that lodge themselves into the skin of prey and release toxins. The toxin stuns the prey long enough for the jellyfish to transfer its new meal to its mouth.
- Common Names: Lion’s Mane Jellyfish, Hair Jelly, Arctic Red Jellyfish, Giant Jellyfish
- Lion’s Mane Jellyfish Scientific Name: Cyanea capillata
- Origin: Pacific and Atlantic Oceans and the North Sea
- Lion’s Mane Jellyfish Size (Length): Up to 120 ft (36.6 m) long
- Lion’s Mane Jellyfish Weight: 200 lbs (90.7 kg)
- Lifespan: About 1 year
Lion’s Mane Jellyfish Habitat
A lion’s mane jelly lives in the open ocean (pelagic region) of the Pacific and Atlantic Oceans and the North Sea.
They prefer areas of the ocean that are cold, so they are most common in the Arctic and North Pacific Ocean. You are most likely to see them in waters between Alaska and Washington.
Jellyfish that live further north tend to grow much larger than those that live in lower latitudes.
They live near the surface of the ocean, rarely traveling lower than 65 ft (20 m) below the ocean’s surface.
What Does A Lion’s Mane Jellyfish Eat?
The lion jellyfish eats mostly fish. The University of Michigan Museum of Zoology describes its feeding habits:
“It catches its prey by sinking slowly with its tentacles spread in a circle around it. The prey is captured in the “net” of tentacles and stunned by the nematocysts.”
Behavior & Temperament
Because of their enormous size, lion’s mane jellyfish can cover long distances in a short amount of time. They drift along the strong currents of the ocean, continuously swimming.
Lion’s manes are solitary animals, but you may see large swarms when there are strong currents or storms.
A sting from a lion’s mane jelly is more toxic than many other jellyfish species, but they’re rarely fatal. A sting by these jellyfish offers a range of symptoms. People may simply get a painful rash, while others have adverse respiratory function.
Their stings are sometimes fatal, but humans rarely come across these jellyfish, so stings are rare. They live in the open ocean (pelagic region), rather than near the coast where people like to swim.
Researchers say that fish will often use the jellyfish’s tentacles as protection against predators.
The Australian Museum says “Large individuals often have many small fish that live near the bell of the jellyfish and avoid the stinging tentacles. This gives the fish protection from predators, as few animals will approach a large Lion’s Mane Jellyfish.”
Lion’s Mane Jellyfish Reproduction
These jellyfish breed from March to early May, reproducing via sexual reproduction. As adults, lion’s mane jellyfish are either male or female. When it’s time to mate, females release eggs, and males release sperm into the open water via external fertilization.
In most jellyfish species, the eggs are on their own from the time they’re released, receiving no care from the mother. But, female lion’s mane jellyfish hold their fertilized eggs within their oral arms until they are ready to hatch and develop into larvae.
Then, the larvae will settle and attach to the sea floor as polyps who resemble coral with tentacles. Jellyfish polyps can reproduce asexually, creating genetically identical clones of themselves.
The polyps develop into juvenile, free-swimming jellyfish called ephyra in about 30-40 days.
Then, the ephyra grows into an adult lion’s mane jellyfish called a medusa. Lion’s mane jellyfish don’t have a long lifespan, only living for about one year.
Lion’s Mane Jellyfish Predators
Massive leatherback turtles feast on lion’s mane jellies — their primary food source. The thick scales on these turtles protect them from getting stung by the tentacles. Papillae, spiny and fleshy projections, line the leatherback’s esophagus. The papillae help the sea turtle break down the jellyfish. The painful sting of jellyfish doesn’t seem to affect sea turtles.
Some fish, like the southern harvestfish and gulf butterfish, are immune to the lion’s mane’s toxins, so they frequently feed on them.
Conclusion
The lion’s mane jelly is the biggest jellyfish in the world with tentacles that can reach incredible lengths of up to 120 ft (36.6 m). Their size, coupled with their many tentacles and vibrant colors makes them an amazing sight to behold. Still, you’re unlikely to come across these animals in the wild since they prefer the cold open ocean.
FAQs
Lion’s mane jellyfish are massive, but their toxins are rarely fatal to humans. How a sting affects someone often depends on the individual. Many people simply feel a sting that isn’t all that painful. Others experience an allergic reaction that causes them to break out in a rash.
In the most severe cases, a sting from a lion’s mane may cause an adverse respiratory reaction. Fatalities have occurred because of a lion’s mane sting, but it’s rare.
Lion’s mane jellyfish are bioluminescent, meaning that they can glow. These jellyfish likely use bioluminescence to lure prey to them so they can grab and stun them.
The International Union for the Conservation of Nature (IUCN) has not assessed the lion’s mane jellyfish, but their populations are abundant and are not in danger of extinction.
