The Largest Jellyfish in the World
Considered the largest known jellyfish in the world, the lion’s mane jellyfish (cyanea capillata) could be a beach swimmer’s worst nightmare, aside from killer whales and sharks of course. On record, the largest one laid bare for actual measurement based on a specimen washed up on the shore of Massachusetts Bay in 1870 yielded a dimension of 2.3 m (7 feet 6 in) in diameter and tentacles 36.5 m (120 feet) long.
Considered less dangerous than the types of jellyfish that should be avoided, a lion’s mane jellyfish encounter could only cause temporary pain and localized redness on points of contact on human skin. It was only depicted with exaggeration when a lion’s mane jellyfish encounter was portrayed on a Sherlock Holmes story, “The Adventures of the Lion’s Mane” where a professor is mysteriously killed and the protagonist pinpointed the killer to be a huge jellyfish. As the moral of the story shows, the victim turned out to be weak hearted not the fact that lion’s mane jellyfish is capable to cause fatal stings. So if you are out on the beach and you see one near, take it casually. If you have a history of heart ailment however, don’t push your luck as it will not be the sting that could knock you down.
A bell diameter of 2.5 m (8 feet) has proven attainable for lion’s mane jellyfish but sizes may vary greatly according to locations, those found in the lower latitudes are generally smaller than their far northern counterparts with bells about 50 cm (20 in) in diameter. Average tentacles could grow as long as 30 m ( 90 feet or more) which are extremely sticky and grouped into 8 clusters. Each clusters could average 100 tentacles arranged in rows.
Lion’s mane jellyfish mainly depend on ocean currents to direct their movement. They usually prefer very near the surface no deeper than 20 m in depth. Usually spotted in late summer and autumn, they grow larger in size where the currents drive them ashore. They are coldwater species and can’t usually adapt to warmer waters. When in open sea, they provide habitat for other marine animals as floating oases (like an isolated patch of vegetation in the desert). Shrimps and fishes may find a suitable refuge in it against predators while providing a reliable source of food. Lion’s mane jellyfish becomes prey to seabirds, larger fish, sea turtles and other jellyfish species. Free from these predators, it feeds on zooplankton, small fish and moon jellies and could endure a lifespan of a year.