Tell some amazing facts about Jellyfish ?

Jellyfish first appeared about 650 million years ago and are found in every ocean, from the surface to the deep sea. Some are also found in fresh water

Medusa (plural medusae) is another word for jellyfish. Medusa is also the word for jellyfish in: Greek, Finnish, Portuguese, Romanian, Hebrew, Serbian, Croatian, Spanish, French, Italian, Hungarian, Polish, Czech, Slovak, Russian and Bulgarian

Since jellyfish are not actually fish, some people consider the term jellyfish a misnomer, and American public aquariums have popularized use of the terms jellies or sea jellies instead

A group of jellyfish is called a bloom or swarm

Jellyfish do not have a respiratory system since their skin is thin enough that the body is oxygenated by diffusion

Jellyfish do not have a brain or central nervous system, but rather have a loose network of nerves, located in the epidermis, which is called a “nerve net.”

Jellyfish are composed of more than 90% water. Most of their umbrella mass is a gelatinous material (the jelly) called mesoglea, which is surrounded by two layers of cells which forms the umbrella (top surface). The subumbrella (bottom surface) of the body is known as the bell

. Jellyfish are dioecious; that is, they are either male or female. In most cases, to reproduce, both males and females release sperm and eggs into the surrounding water, where the (unprotected) eggs are fertilized and mature into new organisms

Box jellyfish venom is the most deadly in the animal kingdon and has caused at least 5,568 recorded deaths since 1954. Each tentacle has about 500,000 sindasites which are harpoon shaped needles that inject venom into the victim

The lion’s mane jellyfish is the largest known species of jellyfish. The Arctic Lion’s mane jellyfish is one of the longest known animals and the largest recorded specimen had a bell (body) with a diameter of 2.3 m (7 feet 6 inches) and the tentacles reached 36.5 m (120 feet). It was found washed up on the shore of Massachusetts Bay in 1870

1. JELLYFISH CAN STING WHEN THEY'RE DEAD.

Even when they’re attached to a carcass, the cells of a jellyfish’s venomous tentacles will sometimes continue to fire: In 2010, about 150 New Hampshire beach-goers were stung by the disembodied tentacles of a dead lion’s mane jelly.

From the outside, jellyfish look like squishy, insubstantial blobs, and this is reflected in their structural makeup.  Jellyfish are 95 percent water with the rest of them accounting for minerals and proteins.

Between their two dermis layers is a gelatinous, water-based substance called mesoglea that contains muscle cells, nerve cells, and structural proteins.

Nuclear power plants in Scotland, Sweden, California, Israel, and Japan have all been taken offline by slimy swarms of jellyfish.

Power plants use outside water sources to cool down the fuel rods inside their reactor core. If this water contains jellies, they can clog up the system and force plants to shut down.

At any stage in its development, Turritopsis dohrnii—also known as the “immortal jellyfish” or the “Benjamin Button jellyfish”—is capable of reversing its life cycle until it reverts to a polyp, from which it starts the whole process over again.

Some scientists believe by aging backward to escape death this jellyfish has unlocked the key to immortality.

Jellyfish have inhabited the earth’s oceans for over 650 million years, making them more ancient than sharks and dinosaurs.

The Phialella zappai was named in honor of Frank Zappa, the favorite musician of the scientist who discovered it.

In 1991, NASA made history by sending 2478 jellyfish polyps to space. It was part of an experiment called “The Effects of Microgravity-Induced Weightlessness on Aurelia Ephyra Differentiation and Statolith Synthesis.”

The creatures were kept in flasks and bags that contained artificial seawater, which astronauts then injected with chemicals that encouraged them to reproduce.

By the end of the experiment there were approximately 60,000 jellyfish in the Earth’s orbit.

Jellies don’t have lungs, intestines, or stomachs, but they do use a much simpler system that’s able to get the job done.

Their bodies are composed of two cell layers—the external epidermis and the internal gastrodermis. The gastrodermis has one opening it uses to consume food, expel waste, and exchange reproductive materials.