Tell some amazing facts about Jellyfish ?

While jellyfish do not have a brain, they have an elementary nervous system with receptors that detect light, vibrations, and chemicals in the water. These abilities, along with the sense of gravity, allow the jellyfish to orient and guide itself in the water

Jellyfish are invertebrates, which means they are animals without a skeleton. Approximately 95% of their body is water

Jellyfish are usually seen in shallow coastal water; however, scientists have discovered a few species that live at depths of 30,000 feet (9,000 meters). While most jellyfish prefer warm water, some live in subarctic temperatures

A jellyfish tentacle can still sting even if it is separated from the jellyfish’s body

The smallest jellyfish in the world is the creeping jellyfish. It has bell disks from 0.5 mm to a few mm in diameter. It reproduces asexually by splitting in half. Another contender for the smallest jellyfish is the extremely toxic Australian Irukandji, which is only the size of a fingernail.

The largest jellyfish in the world is the Nomura’s jellyfish. Other candidates for the largest jellyfish are the Lion’s mane jellyfish and the Stygiomedusa gigantea.

The giant jellyfish called Stygiomedusa gigantea has been seen only 17 times in the last 110 years.

The Portuguese man-of-war looks like a jellyfish, but it is not a true jellyfish. In fact, it is not even a single animal. It is a siphonophore, which is an animal made up of a colony of organisms that work together. Specifically, the man-of-war consists of four separate polyps. The top polyp is a gas-filled bladder that reminded people of the sails on a once common ship called a man-of-war

Jellyfish produce both asexually and sexually. They are usually male or female, though hermaphroditic species have also been found

Jellyfish live from a few hours to many months. One species has been reported to live as long as 30 years. Jellyfish in aquariums typically live longer than those in the wild. Because jellyfish are so fragile, it’s easier for people to capture jellyfish in the polyp stage when they are the least vulnerable

Most jellyfish are passive carnivores. They feed on plankton, crustaceans, other jellyfish, fish eggs, and small fish. They eat and void through the same hole in the middle of the bell

Jellyfish have several predators, including other jellyfish, sharks, tuna, swordfish, sea turtles, and one species of Pacific salmon

One species of jellyfish, the Turritopsis nutricula, is also known as the “immortal jellyfish” because it can transform from the mature medusa state back to the polyp state, thereby essentially avoiding death. It accomplishes this through the cell development process called transdifferentiation

The type of jellyfish most seen on the shores of North America and Europe is the Moon jellyfish. This type of jellyfish is typically blue or pink and is found in waters approximately 20 feet (6 meters) deep. Its sting is usually mild, but can leave an itchy, red rash

Even a dead jellyfish can sting

Jellyfish have lived in the waters of the world for more than 650 million years, long before the dinosaurs, making them the oldest multi-organ anima

Portuguese man-of-wars can grow to be 165 feet (50 meters) long, although 30 feet is more typical. On a baseball diamond, they would reach from home plate to first base and more than halfway to second. Man-of-wars can sometimes be seen in groups of 1,000 or more floating in warm ocean waters. To avoid threats, they can deflate their air bladder and briefly sink under the water

The upside-down jellyfish does not float in the water. Instead, it anchors itself to the ocean floor, with its short arms and tentacles reaching up. It looks like a bowl of plants rather than a typical jellyfish.

Crabs have been known to hitchhike on jellyfish
Crabs have sometimes been seen hitching a ride on a jellyfish. The hard, outer shell of the crab protects it from the jellyfish’s sting. The crab also usually catches a little of the food the jellyfish traps

There are more than 2,000 different types of jellyfish. Approximately 70 can hurt people, with the box jellyfish (Chironex fleckeri) being the most dangerous. Scientists believe that there could be as many as 300,000 different species of jellyfish yet to be discovered

Jellyfish are not fish. They are actually plankton from the phylum Cnidaria (Greek for “stinging nettle”) and the class Scyphoza (from the Greek “cup”). Some aquariums are trying to popularize the terms “jellies” or “sea jellies” instead of jellyfish.

Jellyfish move in essentially two ways. They take water in their bell and then squirt it out behind them, which creates a jet of water that moves them forward. They also drift on water currents.

The body of a jellyfish has six parts. The inner layer is the gastrodermis, which lines the gastrovascular cavity. The middle layer is a thick substance called the mesoglea. The outer layer is the epidermis. It also has an orifice and tentacles.

Researchers suggest that the shipping industry has artificially distributed jellyfish into nonnative habitats where they then colonize. Ships transport jellyfish around the world in two ways: 1) juvenile jellyfish (polyps) attach to ship hulls and travel with them and 2) ships take on ballast water in originating harbors and then dump their ballast water (along with jellyfish and other organisms) in new waters. Billions of gallons of ballast water are transported annually around the globe

Jellyfish are aggressive colonizers. Eight years after comb jellyfish were introduced into the Black Sea in 1982, they totaled about 900 million tons. Jellyfish have caused $350 million in losses to the Black Sea’s fishing and tourism industries.