Most And Least

Most Venomous Marine Creature

The Box Jellyfish, named for their cubically shaped body body, is the most venomous creature to live under the sea. It has caused 5,567 recorded deaths since 1954, but the deaths which were unrecorded are of course much more. The jellyfish’s venom is the most poisonous in the world, it contains toxins which instantly attach the heart, nervous system, and the skin cells.

The scary part is that the venom is extremely powerful, as well as overwhelmingly painful, such that human victims go into shock, causing drowning, or die of heart failure even before they receive help or reach shore. Those who survive, suffer through a number of problems, and experience pain for many weeks. The venom of box jellyfish has cardiotoxic, neurotoxic and highly dermatonecrotic components, which rapidly absorb into the human body, and become part of the circulation. The tentacles which inject the poison become sticky and adhere tightly to the skin. When one tries to remove the tentacles while they are still active, it worsens the impact, and lead to greater injuries.

Image Credits: brisbanetimes

A diver with a Box Jellyfish

Medical Treatment

Once stung by the jellyfish, unless and until there is immediate medical help available, the human being has very little chance to survive. If no medical help is available, the first and foremost thing to do would be to apply domestic vinegar (never methylated spirits) to the sting. Vinegar has acetic acid, which fights against the venomous cells that have not yet discharged into the bloodstream. This will not alleviate the pain, but will definitely reduce the amount of poison being inserted into the bloodstream. When the tentacles become inactive, they can be safely removed. Where antivenom is not available, pressure-immobilization of the limbs may be used after inactivation of nematocysts (stinging cells) while the patient is transported to hospital.

Appearance

The jellyfish is luminous, pale blue or transparent in color, bell or cubic shaped. It measures to around 20 cm long on each side of the cube, and it has around 15 tentacles which releases the poisonous venom. The tentacles can grow up to 3 meters in length, and has an average of 5,000 nematocysts. Its movement is like a jet, i.e. it contracts, and then when it releases itself, the force produced allows it to shoot forward, up to speeds of 4 knots.

Image Credits: JLambus

Luminous Box Jellyfish, which can have ten to sixty stinging tentacles.

At times, because of its transparency, it can barely be seen, and almost seems invisible. They also have eyes! The eyes are grouped in clusters of six, on each of the four sides of their box shaped body. The eye has a sophisticated lens, retina, iris and cornea. Since they have no central nervous system, scientists are researching as to how the jellyfish actually sees.

Photograph by David Doubilet

An almost transparent Jellyfish

Life-cycle and Existence

They exist in the coastal waters of Northern Australia, in the Phillipines, Hawaii, Vietname and most tropical areas, where they are rampant in the warm water just offshore. Australia summertime, which takes place from November to April and May sees a vast number of jellyfish in the warmer waters.

Adult jellyfish spawn at river mouths in late summer, and the female lays the eggs which attach themselves to rocks in the form of tiny polyps. When spring arrives, these polyps grow into small jellyfish, which feed on shrimps. Jellyfish are often found on beaches, and are attracted to humans.

In spring, these polyps develop into small jellyfish that migrate downstream, especially with rains. They feed on shrimps and often frequent beaches that are attractive to humans.

A jellyfish waits in a passive mode, until its prey bumps into their tentacles. At that moment, they sting their prey and release their venom. A struggling shrimp can tear a young jellyfish, it needs to be killed instantly with a very strong poison.

The jellyfish’s mechanism of stun and kill is a mechanism to protect the delicate tentacles which release the poison. After all, all creatures need to protect themselves in the survival for fitness. For humans, wearing panty hose while swimming is also a good prevention measure since it can prevent jellies from stinging and would not be able to harm your legs. Snorkelers and scuba divers are encouraged to wear “stinger suits,” full-body protective gear. Swimming is also allowed within nets that prevent box jellies from entering.

Image Credits: zoltantakacs

Safety Signs for Marine Jellyfish

Image Credits: Wikipedia.com

Box net on beches where Box Jellyfish is present

Some marine species (such as turtles) are immune to the venom, and are known to feed on the jellyfish.

Note: the pictures are not mine, but from the Internet. If the photographer of any of these pics sees his/her work, please leave a comment and I will be happy to give the credit to you.