Box Jellyfish

 
They live off the coast of Northern Australia and throughout the Indo-Pacific Ocean. They are see-through, nearly invisible, and their long tentacles pack a toxic punch that will leave you unconscious in the water. They are Box Jellyfish, also called Sea Wasps, for their deadly sting.

One of the most toxic animals in the world, this jellyfish’s sting causes heart and nervous system failure. Although it rarely kills an adult human, it can lead to death by drowning for adults stung while swimming in deep water. However, if you’re sea turtle, don’t worry. You’re naturally immune. Everyone else, though, should swim like crazy to get away from them.

This jellyfish has clusters of 6 eyes on each side of its cube-ish body, for a total of 24 eyes. One set on each side is highly advanced, but scientists are still unsure of how it processes what it sees without a brain. Box Jellies have up to 15 tentacles and grow about 10 ft long, but less than a foot wide. They eat small fish and crustaceans, first stinging them to paralyze or kill them.

The life cycle of the box jellyfish begins when the free-swimming planula is formed from the reproductive cells. The planula develops into a polyp (larva) which attaches itself to the sea floor. A polyp can reproduce itself, forming new polyps. Polyps undergo metamorphosis into medusa, miniature versions of adult box jellyfish. They will return to coastal waters to grow into adults.