It’s not just the deadly box jelly when it comes to jellyfish of Australia — these waters are home to many amazing species. Watch out for both the deadly and delightful on your next dive Down Under.

When considering jellyfish of Australia, most people think immediately of the deadly box jellyfish. These famous jellies are known for stinging and badly injuring or killing unsuspecting divers and snorkelers. While these nasty cnidarians do cause chaos, Australia is home to multiple amazing species of jellyfish that rarely sting but often amaze divers. So, when you dive in Australia watch out for both the deadly and delightful. Here are our picks for the top four species you might find in these waters (including the box jelly).

Box jellyfish

Despite their fearsome reputation, most of these jellyfish are harmless to humans. However, in the northern parts of Australia two deadly species do inhabit the waters during the summer.

Chironex fleckeri, commonly known as the sea wasp, is the common name for the most dangerous of Australia’s box jellies. Deaths are, however, relatively rare with less than 10 percent of people who suffer stings requiring hospitalization. Most healthy divers will experience only a painful burning sensation if they come in contact with one. Children make up the bulk of deaths from a C. fleckeri sting, due to their smaller body mass. Wearing a full-body dive skin or rash vest at the very least can help prevent these stings while also keeping you warmer in the water and safe from the strong Australian sun.

Lion’s mane jellyfish

These giants are the largest known species of jellyfish. The largest-ever recorded specimen had a bell with a diameter of 7 feet, 6 inches (2.3 m) and tentacles of 121 feet (37 m) long. More typical specimens have bells of 3.2 feet (1 m) across and tentacles 33 feet (10 m) long. While they do possess stingers, only rare cases involving allergies have caused problems for ocean goers. Divers often spot them in the southern regions of Australia but unfortunately the animals that live in the colder waters don’t reach as prolific a size as their tropical relatives. Turtles often feed on them and thus they’re an integral part of ocean food chains. Lion’s mane jellyfish often have beautiful, deep reds within their domes, and those rich colors coupled with multiple tentacles give them an extraterrestrial vibe.

Haeckel’s jellyfish

These magnificent jellyfish are a treat to see on a dive. You’ll often find them in shallow waters near the shore, especially in enclosed bays. Here, given the right weather conditions, large populations can become trapped. Multiple species of small fish often live within these jellyfish, using them as both a food source and a form of protection from the predators in the open ocean. You can distinguish these jellyfish by their beautiful clear and lumpy domes which, along with their multiple arms, contain stinging cells. Fortunately, they only cause minor irritation. 

Comb jellyfish

While not technically classed as jellyfish, their bodies are primarily made up of a type of gelatinous jelly similar to jellyfish. These banana-like animals move through the sea by using hundreds of tiny hairs along the ridges of their bodies. It is these ridges that make them such a spectacular sight — look closely and you will see vibrant colors pulsating up and down as these animals beat their cilia in unison. Comb jellyfish are completely harmless with no stingers.

Have something to add to this post? Share it in the comments.
New stuff
sardine run

Top Tips on the Sardine Run in South Africa

The sardine run along the South African coast is one of the largest marine-life migrations on earth. Here's all you need to know about this extraordinary event.
by Juanita Pienaar
explorer ventures

Explorer Ventures Liveaboard Fleet Announces Two New Boats

Explorer Ventures liveaboard fleet announces the addition of two new boats: one in Indonesia and one in the Galapagos
by Press Release
technical diving

The ABCs of Technical Diving: X through Z

In the last installment of our tech-diving ABCs series, we’re looking at the letters X, Y and Z, starting with X-over (crossovers) and finishing with Z-knives.
by Yvonne Press

First Study of World’s Smalleye Stingray Reveals Long-Distance Migration

Scientists from the Marine Megafauna Foundation have for the first time used photo IDs to study the elusive smalleye stingray in southern Mozambique.
by Press Release