Jellyfish are one of the most enchanting creatures that exist in our marine kingdom. There are so many species of jellyfish and so many new are discovered at such alarming regularity that it is impossible to know for sure how many varieties of these creatures live in our oceans. What we do know is that they can be found in every sea and ocean of the world. The different varieties of jelly fish exist in different habitats ranging from the warm temperate waters of the tropical oceans to the harsh and freezing waters of the Arctic Ocean. What we also know is that jellyfish have existed on this planet for about 650 million years and there is a possibility that they were the first organisms to detach themselves from the bark of a tree and initiate the existence of the animal kingdom on this planet.

One of the reasons that jellyfish have outlasted a number of species that are extinct today and still continue to grow in large numbers is their fantastic defense mechanism which allows them to escape predators and prevent the dwindling of their numbers. Their secret weapon against extinction is their tentacles.

Most species of jellyfish have long extending tentacles at the margin of their gelatinous bodies. The number of tentacles varies from species to species and can range between eight tentacles and over hundreds of them. The lengths of the tentacles also depend upon the species of the jellyfish and vary between a few feet to over a hundred feet. The biggest known jellyfish is the Arctic Lion's Mane whose tentacles extend to over 120 feet.

The tentacles of the jellyfish are equipped with venom apparatus to help them procure food and defend them against predators. This specialized venom apparatus is called cnidoblast and consists of capsule-like structures called nematocysts. These nematocysts contain both the trigger and the venom that leads to a jellyfish sting. Nematocysts are present on the tentacles or oral arms or both depending on the species of the jellyfish. There can be thousands of nematocysts lining the tentacles of a jellyfish. The nematocysts are hollow and contain a coiled thread inside them. These threads contain the venom of the jellyfish inside them and are lined with barbs on their sides.

When the nerve endings on the nematocysts feel any pressure, they immediately get activated. When this happens, the thread inside the nematocysts begins to uncoil rapidly and is shot into the flesh of the predator or the prey, where they attach themselves with the help of the barbs. The toxic venom of the jellyfish then gets injected into the flesh and start spreading immediately.

Jellyfish use their tentacles to catch their prey. Once the prey has been killed by the venom, the tentacles help transport the food to the mouth of the jellyfish. The tentacles also help the jellyfish to defend themselves against predators. Even if the sting doesn't necessarily kill the large predators of the jellyfish, they are capable of having a paralyzing effect on them, which gives the jellyfish enough time to escape.
Normen FAdel
Author of the article
writer and blogger, founder of jellyfish .

New of label : Jellyfish Bodies & Feeding

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