Box Jellyfish

Box Jellyfish are pale blue, transparent and bell or cubed shaped with four distinct sides. Measuring up to 20 cm along each side of the cube or bell, the Box Jellyfish has up to as many as 15 tentacles on each corner which can be 3 metres in length with up to 5,000 nematocysts (stinging cells). It weighs upto 4.4 lbs or 2 kg. It shoots itself along up to speeds of 4 knots in a jet-like motion. They are known for the extremely potent venom produced by some species.

Box jellyfish most visibly differ from the "true" or Scyphozoan jellyfish in that their umbrellas are cubic, rather than domed or crown-shaped. The underside of the umbrella includes a flap, or velarium, concentrating and increasing the flow of water expelled from the umbrella. As a result, box jellyfish can move more rapidly than other jellyfish, with speeds of up to six meters per minute having been recorded.

The box jellyfish's nervous system is also more developed than that of many other jellyfish. Notably, they possess a nerve ring around the base of the umbrella that coordinates their pulsing movements; a feature found elsewhere only in the crown jellyfish. 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.

The box jellyfish seem to move towards the shore in calm waters when tide is rising and gather near the mouths of rivers, estrays and creeks following the rain. Box Jellyfish feed on small fish and crustaceans.

Although the notoriously dangerous species of box jellies are largely, or entirely, restricted to the tropical Indo-Pacific, various species of box jellies can be found widely in tropical and subtropical oceans, including the Atlantic and east Pacific, with species as far north as California, the Mediterranean and Japan and as far south as South Africa and New Zealand.

In northern Australia, the highest risk period for the box jellyfish is between October and May, but stings and specimens have been reported all months of the year. Similarly, the highest risk conditions are those with calm water and a light, onshore breeze; however, stings and specimens have been reported in all conditions. In Hawaii, box jellyfish numbers peak approximately 7 to 10 days after a full moon, when they come near the shore to spawn.

The box jellyfish has been called the world's most venomous creature. Each tentacle has about 5,000 nematocysts (stinging cells), harpoon-shaped needles that inject venom into the victim. You have virtually no chance of surviving the venomous sting. The pain is so excruciating and overwhelming that one would most likely drown before reaching the shore.

Domestic vinegars should be poured liberally over the tentacles to inactivate stinging cells as soon as possible. The tentacles may then be removed. Artificial respiration and cardiac massage may be required.