top of page

Jellyfish, Anemones and Corals

Group 7: Cnidaria


Group 6 - Cnidaria: Phylum Cnidaria consists of over 11,000 individual species of aquatic animals, including jellyfish, anemones and corals.

Choose an Invertebrate Category

5 Fun Facts - Cnidaria

Fun Facts Cnidaria

Cnidarians range in size from almost microscopic to over thirty meters in length and can be found in nearly all marine ecosystems.

Body Shape: Cnidarians are radially symmetric, meaning all parts of the organism are arranged around a minn axis. They do not have an obvious front or back, and they do not have a head. Instead they have two sides. The oral side has a centralized mouth surrounded by tentacles; the opposite side is known as the aboral side.

Differences: There are two main types of cnidarians: polyps and medusae. Polyps such as corals are genereally sessile. Medusae such as mature jellyfish, free float or swim.

Reproduction: Cnidarians can reproduce either asexually or sexually, depending on their life stage and form. They reproduce through the same methods as sponges. Polyps reproduce through fragmentation, budding or broadcast spawning. Medusae reproduce through spawning or brooding.

Hermaprodites: Many cnidarians are hermaphroditic and can release both sperm and eggs at the same time during spawning.

Classes: Cnidarians are divided into four classes: Scyphozoa (True jellyfish), Cubozoa (box Jellyfish), Anthozoa (Corals and anemones), Hydrozoa (Most diverse class consisting of Fire corals, hydroids and many medusae).

bottom of page