What is a lagoon jellyfish?

A lagoon jellyfish (_Mastigias papua etpisoni_), scientifically known as the box jellyfish, is a species of the class Cubozoa, highly dangerous to humans. It resides in the coastal waters of the North East of Australia and around New Guinea, and is a relatively small jellyfish, with a bell approximately 20–30 centimetres (7.9–11.8 in) across. They possess 24 large bluish eyes (ocelli) which are used to detect shadows that may fall across them, and these are thought to be unique among jellyfish. Each of the four sides of the box-shaped bell possesses about 15 tentacles which can extend to a length of up to 3 m (9.8 ft), and possibly even longer. Each of the tentacles hosts multiple nematocysts, tiny stinging cells used to capture and paralyse prey.

Lagoon jellyfish are voracious predators that mainly feed on small fish and crustaceans. This jellyfish is often regarded as one of the most venomous creatures on Earth, but as long as basic safety precautions are followed, humans are unlikely to come into contact with these jellyfish or risk being harmed by them.