Box Jellyfish, Box Jellyfish Pictures, Box Jellyfish Facts

Photo: A box jellyfish beneath the water's surface

The box jellyfish's venom is among the most deadly in the world, containing toxins that attack the heart, nervous system, and skin cells.

Photograph by David Doubilet

Map

Box Jellyfish Range

Fast Facts

Type:: Invertebrate
Diet:: Carnivore
Average life span in the wild:: Less than 1 year
Size:: 10 ft (3 m) long; 10 in (25 cm) across
Weight:: Up to 4.4 lbs (2 kg)
Group name:: Fluther or smack
Did you know?: Sea turtles are unaffected by the sting of the box jellyfish and regularly eat them.
Size relative to a 6-ft (2-m) man:

The infamous box jellyfish developed its frighteningly powerful venom to instantly stun or kill prey, like fish and shrimp, so their struggle to escape wouldn’t damage its delicate tentacles.

Their venom is considered to be among the most deadly in the world, containing toxins that attack the heart, nervous system, and skin cells. It is so overpoweringly painful, human victims have been known to go into shock and drown or die of heart failure before even reaching shore. Survivors can experience considerable pain for weeks and often have significant scarring where the tentacles made contact.

Box jellies, also called sea wasps and marine stingers, live primarily in coastal waters off Northern Australia and throughout the Indo-Pacific. They are pale blue and transparent in color and get their name from the cube-like shape of their bell. Up to 15 tentacles grow from each corner of the bell and can reach 10 feet (3 meters) in length. Each tentacle has about 5,000 stinging cells, which are triggered not by touch but by the presence of a chemical on the outer layer of its prey.

Box jellies are highly advanced among jellyfish. They have developed the ability to move rather than just drift, jetting at up to four knots through the water. They also have eyes grouped in clusters of six on the four sides of their bell. Each cluster includes a pair of eyes with a sophisticated lens, retina, iris and cornea, although without a central nervous system, scientists aren’t sure how they process what they see.

Invertebrate Videos

Other Stinging Animals

Invertebrate Features

Coral

It's reef madness in this colorful gallery of coral formations.
Photo Gallery: Coral Reefs

About 80 percent of all life on Earth is found in the oceans, which cover 71 percent of the planet's surface. Take a look at how colorful life under the sea can be.
Lobster

Learn more about these popular crustaceans that some think of only as a meal. Find out the sizes that these sea creatures are capable of attaining.
Sea Cucumber

Learn how these amazing echinoderms deter predators by snaring them with sticky threads and even hurling their internal organs about.

Please select a test to run

On Nat Geo WILD

TV Schedule »

Animal News

Animals

Animal News

Special Ad Section

From the Magazine

Gannets Pictures

Champion divers but clumsy landers, doting parents but hostile neighbors—northern gannets abound in contradictions.
Estonia's Ural Owls

Photographer Sven Začek provides an intimate view of this large raptor.