Jelly fish is the oldest multicellular animals on earth. jelly fish actually they dont have brain. they live in sea,oceans,etc. there are many species in jelly fish. there are about 200 described species.in that box jelly fish is the most dangerous animal on this earth . it is most dangerous than king cobra .

  The jelly fish is mainly made up of Lacking brains, blood, or even hearts, jellyfish are pretty simple critters. They arecomposed of three layers: an outer layer, called the epidermis; a middle layer made of a thick, elastic, jelly-like substance called mesoglea; and an inner layer, called the gastrodermis. they look very inocent. So how does a jellyfish live without these vital organs? Their skin is so thin that they can absorb oxygen right through it, so they don’t need lungs. They don’t have any blood so they don’t need a heart to pump it. And they respond to the changes in their environment around them using signals from a nerve net just below their epidermis - the outer layer of skin - that is sensitive to touch, so they don’t need a brain to process complex thoughts.

The jellyfish is killed by Predation. Other species of jellyfish are among the most common and important jellyfishpredators. Sea anemones may eat jellyfish that drift into their range. Other predators include tunas, sharks, swordfish, sea turtles and penguins.

  jelly fish have super long tantacles . they are known asw survival master . they can be most dangerous and in some case they are not .Jellyfish are among the most abundant organisms in the sea. Recent research suggests there are about 38m tonnes of them just in the epipelagic, the upper 200 metres of ocean. What’s more, they are common in all oceans and have colonised the majority of marine habitats including the deep sea.

One reason they are so common is that contrary to appearances, a body made from jelly is a very successful strategy. Gelatinous bodies have evolved independently three times and have existed, largely unchanged, for at least 500m years, surviving all five major extinction events in the Earth’s past that wiped out 99% of all life.

  They have super powers the moon jelly fish can release 400,000 young ones at a time. 

  some people enjoy meeting jelly fish and having taste of them. but the jelly fishs are really fantastic their look is awesome.