Cnideria Characteristics

Symmetry
They have radial symmetry, meaning they have symmetry around the central axis or origin.

Reproduction
They reproduce both asexually and sexually. Some Cnidarians reproduce by budding of an adult. In other cases, the medusa, the adult version of a polyp, mate with other medusa to create offspring.

Organs
Cnidarians have tentacles tipped with stinging cells that paralyzes or harms prey. In order to retrieve food, Cnidarians, either movable or sessile, capture prey.

Polyp
A polyp is a simply animal that reproduces asexually. These are sessile, meaning they cannot move from one place to another. A few examples are sea anemones and coral.

Polyps have a stem-like structure with tentacles protruding on top of it.

Medusa
A medusa is a free-swimming organism that reproduces through sexual process.

An example is the jellyfish.

Medusa have an umbrella-shaped body, having the mouth being at the bottom.