The jellyfish is an important plankton in the aquatic environment. It is a very beautiful aquatic animal. Its body shape is like a transparent umbrella, and the diameter of the umbrella body is large and small, big jellyfish umbrella diameter of up to 2 meters.

The edge of the umbrella-like body has several tentacles, some tentacles can be 20-30 meters long.

The body of jellyfish is mainly composed of water, and is composed of two inner and outer layers, between the two layers there is a very thick rubber layer, not only transparent but also has the function of floating.

When they move, using the body of the water reflection forward, from a distance, like a round umbrella in the water quickly floating. Some jellyfish have colorful patterns in their umbrella bodies. Swimming in the blue sea, these colorful jellyfish are very beautiful.

A jellyfish is a cellular animal with a simple structure. They have no muscles or bones and are 98 percent water, but some jellyfish can glow. A ctenophore, for example, swims in the ocean, its body a spherical blue glow, its long tentacles behind it glowing with thin bands of light. Bend and wiggle with the body of a ctenophore as it swims.

Some jellyfish have special glands in their bodies that produce a weak biological current. The jellyfish itself is transparent, so the current inside can be seen outside, and that's why they glow.

Despite their beautiful and docile appearance, jellyfish are quite fierce. Underneath the umbrella, those slender tentacles are its digestive organs and its weapons.

The tentacles are covered with stinging cells that shoot venom. When the prey is stung, it quickly becomes paralyzed and dies.

The tentacles latch onto the prey, draw them back, and hold them with polyps under the umbrella, each of which secretes enzymes that quickly break down proteins in the prey.

Because jellyfish have no respiratory or circulatory systems, only primitive digestive organs, the captured food is immediately digested and absorbed in the column.

Generally stung by jellyfish, you will only feel sunburn pain, and redness. As long as you apply anti-inflammatories or edible vinegar, swelling and pain can be reduced in a few days.

Off the coast of Malaysia to Australia, there are two highly toxic species called the sea bee jellyfish (box jellyfish) and the drag and jellyfish.

If stung by one of these jellyfish, they can become breathless and die within minutes, hence the nickname killer jellyfish. Therefore, when stung by jellyfish, breathing difficulties occur, artificial respiration should be immediately implemented, or injection of cardiac agents.

Jellyfish predate dinosaurs, dating back 650 million years. There are many kinds of jellyfish in different forms, ranging from 10 cm to 100 cm in diameter. It's found everywhere in the ocean.

Only a few species occur in freshwater, most abundant in the shallow waters of tropical and subtropical oceans.

Smaller species can be used as fish prey; Jellyfish salted into food, some species can be used as medicine; Some planktonic jellyfish can be used as current indicators; However, some large jellyfish, such as jellies and rhizostomes, can block or damage nets when they appear in large numbers.