jellyfish

general classification

Jellyfish are sea invertebrate animal group from Scyphozoan class which have transparent body and medusa formed (like umbrella) with tentacles. The members of Coelenterate phylum are more than 200 species that spread in the world. Some kinds of jellyfish like Aurelia and Rhopilima can be consumed by people and can be prey for the other sea animals.

physical appearance

Jellyfish have body like a bell, but people always call it umbrella mass. Jellyfish are composed of more than 90% water. Most of their umbrella mass are gelatinous material called “the jelly”, which are surrounded by two layers of epithelial cells which form the umbrella and sub umbrella of the bell, or body. They have lots of stinging cells on their tentacle legs that tasseled in the water. They have no body sketch. Their mouth always opened in the center. They don’t have any colors. It is transparent.

habitat

Jellyfish live in all of warm and shallow oceans around the world from the surface to the deep sea,like Pacific. Some their species live in brackish water.

behavior

Some of them swim free in the water, but the other jellyfish stick on the substrate with body part that like stalk. Jellyfish float about freely, moving by squeezing water out from beneath their body. When jellyfish stop squeezing, they slowly sink. They use statosis on their tentacle legs to detect the earth gravitation in certain place.

the reproduction

Jellyfish have sex organ that apart between the male and female. Fertilization process produces planula which has cilia and microscopic measured. This larva will stick on substrate at the bottom of the sea and turn into adenoid (Scyphistoma). In this phase, jellyfish experience propagation asexual with budding formation. The result are young medusa that will escape as ephyra. Then they swim free and become jellyfish.

the diet

Jellyfish eat small fish and sea shrimp. So, they also belong to carnivore animal. Every fish when touch the tentacles will be stung by the cells on their legs. The stinging cells can kill a nimble fish around it.

some species

The biggest is Cyanea artika. They have diameter bell body up to 2 meters with 56 meters long of tentacle legs. It can sting shark until die.
Another species is Wasp Bee Under Sea, they are the most poisonous jellyfish in the world. They live in East Australia Sea. They can kill human only in three seconds.
Frigate fish are not kind of jellyfish, but hundreds of polyps which look like jellyfish. Their tentacles length is 15 meters long used to catch a prey.
The poison of chironex and chiropsalmus jellyfish is more dangerous than the snake’s poison. The poison can kill human in thirty seconds.