Lion's Mane Jellyfish

Over the last couple of weeks, Tahuna Beach has seen lots of Lion's Mane Jellyfish washed up along the shore. These fascinating creatures are also known as the world's largest jellyfish and can be found in cooler waters around the coast of New Zealand.

The name Lion's Mane Jellyfish comes from the mass of long, yellowy-brown tentacles that look like the colour of a lion's mane.

They have a short life span of one year or less and during that time their colour changes. The younger jellyfish are a pale pink or yellow colour, then as they age they turn a deep reddish-brown.

These beautiful marine creatures are mostly made up of water - they have no brain, no bones, no heart, nor eyes. Although they don't have a brain they're able to function using sensory nerves. Their tentacles, which have tiny, toxic, stinging cells act as a net to capture and paralyse prey before eating them. Food is digested quickly and an opening found underneath their bell-shaped body acts as a mouth and is also used to discard waste.

Their diet consists of plankton, small crustaceans, fish, and other jellyfish. Due to their size, the larger jellyfish don't have many predators but the smaller ones can be eaten by large fish, sea turtles and sea birds. 

Lion's Mane Jellyfish don't purposely attack people, most stings happen when swimmers accidentally brush against them. Even those washed up onshore can sting, although the sting isn't fatal it can be painful. The recommended treatment if you get stung is to flush the area with seawater to rinse away any tentacles or stinging cells. Then apply heat, to permanently inactivate the venom. Others say dabbing vinegar onto the painful area will ease the stinging sensation.

Jellyfish can move short distances by contracting and relaxing a ring of muscles around their domed-shaped body or bell. The muscles open and close the bell, drawing in water and then expelling it, which pushes it forward. However, jellyfish are mainly controlled by water currents. As the jellyfish gets to the end of their lifespan they aren't as resilient and move to shallow waters to avoid the wild ocean currents. And because they're at the mercy of sea currents it's common to see them washed up on beaches.

Did you know a group of jellyfish is called a smack but when huge numbers of jellyfish appear suddenly it's called a bloom?