For marine coelenterates, jellyfish body is umbrella-shaped, the body is translucent, white, green or yellowish, jellyfish umbrella diameter can exceed 45 cm, the largest up to 1 meter huge, umbrella under the eight thickened (with shoulder) carpal base healing so that the mouth disappeared (replaced by the sucker of the secondary mouth), below the mouth of the carpal carpal with a number of rods and filamentous tentacles, on the dense stinging filamentous capsule, can secrete venom.

Its role is to release venom paralyzed when touching small animals to make food. Jellyfish in the tropical, subtropical and temperate coastal are widely distributed, our habitual jellyfish have umbrella smooth mouth and wrist only filaments of edible jellyfish or both rod-shaped rod-shaped jellyfish, and umbrella with many small warts protruding yellow spot jellyfish.

The life cycle of jellyfish through the fertilization _ eunuch aphid _ ± brio strong arrowhead a hydra-like larvae date transverse body date butterfly date into jellyfish and other major stages. In addition to the sexual reproduction process of fertilization in the body, the jellyfish hydra larvae will also give birth to creeping roots to form foot sacs, and even the transverse body will continue to split into multiple disc-shaped body, in order to asexual reproduction methods to increase the number of individuals.