Not much else but water. Still, the moon jelly (Aurelia aurita) are eaten by predators in the sea; fish, crustaceans, sea anemones and even corals and turtles. Now a new study may explain why these predators bother to eat the gelatinous creatures.
Natural Predators
Among the predators of the jellyfish, the following have been identified: ocean sunfish, grey triggerfish, turtles (especially the leatherback sea turtle), some seabirds (such as the fulmars), the whale shark, some crabs (such as the arrow and hermit crabs), some whales (such as the humpbacks).
Green sea turtles are the main predators of the box jellyfish. These turtles sometimes appear to be immune to the venom of a box turtle due to its protective hard shell. The turtles also use a methodical method to consume a box jellyfish.
Diet. The typical jelly eats small, swimming organisms called plankton: a mixture of tiny creatures like amphipods, copepods and krill. It also eats larval shrimps, crabs, fish and even other jellies.
Leatherback: Leatherback turtles are often known as gelatinivores, meaning they only eat invertebrates such as jellyfish and sea squirts. Flatback: This species will eat everything from seaweed to shrimp and crabs.
Dolphins eat a variety of fish, squid, shrimps, jellyfish and octopuses. The types of fish and other creatures dolphins eat depend on the species of dolphin, where the dolphins live and the wildlife that shares their habitats.
CLAIM: Sea turtles can get high by eating jellyfish, similar to how marijuana intoxicates humans. AP'S ASSESSMENT: False. Jellyfish do not contain properties that would result in sea turtles becoming high when indulging in the gelatinous marine animal, experts told The Associated Press.
Most jellyfish are short lived. Medusa or adult jellyfish typically live for a few months, depending on the species, although some species can live for 2-3 years in captivity. Polyps can live and reproduce asexually for several years, or even decades. One jellyfish species is almost immortal.
Rhopilema esculentum and Rhopilema hispidum are edible jellyfish, and are the most common ones consumed in China, Japan and Korea.
The Australian box jellyfish is considered the most venomous marine animal. They may not look dangerous, but the sting from a box jellyfish could be enough to send you to Davy Jones's locker-a watery grave, that is.
Certain box jellyfish stings can kill a person within minutes. Other box jellyfish stings can lead to death in 4 to 48 hours after a sting due to "Irukandji syndrome," a delayed reaction to the sting. It is important to carefully monitor box jellyfish sting victims for hours after a sting.
Where the jellyfish tentacles have touched the skin, there will be immediate severe pain and red whip-like lines. If there has been a large area of contact, the person's heart may stop, causing death. This can happen within a few minutes.
Jellyfish sting for the same reason many sharks bite, they bump into something they think might be food and try and eat it. Are jellyfish conscious? Jellyfish have no brains and therefore are not aware of their own existence. So no, while alive they are not “conscious”.
Grey triggerfish, ocean sunfish, seabirds, turtles, whale sharks, crabs, and whales eat jellyfish naturally. However, the main predators of jellyfish are usually other different types of jellyfish. The jellyfish is a pelagic fish that lives in the open ocean from the tropics to the Arctic Ocean.
For instance, the gobies are "miraculously" immune to a jellyfish's nasty sting. They've even been seen resting on the organisms's bells, or main body parts, as well as swimming among jellyfish tentacles, Braithwaite said. (See a picture of the deadly box jellyfish.)
The Chinese have been eating jellyfish for a thousand years, and the delicacy has since become popular in Japan and Korea. About a dozen varieties are edible, and the animals are typically soaked in brine and dried or served in strips with soy sauce.
The Irukandji jellyfish exists in the northern waters of Australia. The southern extent of the Irukandji's range on Australia's eastern coast has been gradually moving south. There has been an increased incidence of Irukandji stings reported around Great Palm Island, off the coast of north Queensland near Townsville.
For scientists, however, jellyfish are fascinating research subjects – they play important roles in the marine ecosystem and are a key source of food for some fish and sea turtles. Some even protect commercially valuable species, such as oysters, from predators.
When the medusa the immortal jellyfish (Turritopsis dohrnii) dies, it sinks to the ocean floor and begins to decay. Amazingly, its cells then reaggregate, not into a new medusa, but into polyps, and from these polyps emerge new jellyfish. The jellyfish has skipped to an earlier life stage to begin again.
Of those that do exist, the oldest-known jellyfish fossils, found in Utah, date to 505 million years ago and have enough detail to show clear relationships with some modern species of jellyfish.
If you didn't know there were jellyfish seasons, well now you do! They are usually between the month of March and usually ends around mid-April. But the jellyfishes you'll see during these two months on your snorkels are not really jellyfish per say, though they do belong in the same family!
Jellyfish may now be kept as pets in your own house thanks to the creation of specialized circular aquariums. Pet jellyfish can live for several years if they are properly cared for and fed.
The ability to attack other creatures with a venomous sting may seem like a nasty trait to share with your family members. It's certainly no guarantee you'll get along: Some kinds of jellyfish use their sting to kill and eat other species of jellyfish.
The venom comes from specialised cells called nematocysts and when made in contact with the human skin, the stung one gets could be awful and at times even fatal. Sea turtles however are reptiles, and their scales can protect them from these venoms.