Lion's Mane Jellyfish

Fascinating facts about the Lion's Mane Jellyfish

• A lion's mane jellyfish measured off Massachusetts in 1865 boasted a bell 210 cm (7 ft) wide and tentacles stretching 36.6 m (120 ft), longer than a blue whale and enough to rank it among the longest animals on Earth. That same record-breaking specimen sparked debate because the measurement methods were unclear, yet the sheer scale shows how a gelatinous creature can rival the size of the biggest vertebrates.
• Lion's mane jellyfish inhabit only cold, boreal waters of the Arctic, northern Atlantic and Pacific, thriving in the English Channel, Irish Sea, North Sea and western Scandinavian waters down to Kattegat and Øresund. They occasionally drift into the southwestern Baltic Sea, but the low salinity there prevents breeding.
• The species lives a year-long cycle through four distinct stages: a free-swimming larva, a sessile polyp, a stack of tiny medusae called ephyrae, and the mature medusa. After fertilization, the female holds eggs in a tentacle until they develop into larvae, which she deposits on a hard surface to become polyps. Those polyps reproduce asexually, shedding ephyrae that eventually grow into the full-sized jellyfish.
• Adult lion's mane jellyfish face few predators because of their massive size and potent stinging cells, but leatherback sea turtles rely on them as a major food source during the summer off eastern Canada. This predator-prey link shows how even the most intimidating gelatinous animals support the diet of a threatened megafauna, underscoring the jellyfish's ecological importance beyond its own survival.
• A single broken lion's mane jellyfish can still sting for up to 25 days after detaching, posing a hazard to fish farms and swimmers. In July 2010, about 150 beachgoers were stung by the remnants of one specimen at Wallis Sands State Beach in New Hampshire, illustrating how even dead fragments can cause widespread pain and require medical attention when large numbers of tentacles contact skin.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Lion's Mane Jellyfish

The Lion's Mane Jellyfish is the largest species of jellyfish on Earth. Its bell can exceed two metres in diameter and its tentacles trail up to 37 metres, longer than the longest blue whale ever recorded. Despite its enormous size, it lives for less than a year.

More ocean life to discover

Browse Feravox