Corals, Sea Anemones and Colonial Anemones (Class: Anthozoa)
The members of this class of exclusively marine invertebrates are almost always encountered attached to a marine substrate on or close to the bottom. The group includes the hard and soft corals, sea pens, sea fans, gorgonians and sea anemones
Box Jellyfish (Class: Cubozoa)
A group of cnidarians characterised by their cube-shaped bell (medusa), these fast swimming invertebrates have well-developed eyes for locating prey, mainly zooplankton, crustaceans and fish, which are trapped and immobilised by the venomous tentacles and moved to the mouth, usually while inverted.
Hydrozoans (Class: Hydrozoa)
A diverse group of cnidarians (jellyfish, corals, hydras, sea anemones, sea ferns and related organisms), that inhabit both marine and freshwater environments, and can be colonial (mostly) or solitary in nature. They are mostly characterised by a life cycle that contains a planula larval stage (which normally develops into a sessile polyp) and the medusa stage, a free-swimming breeding stage. They all contain stinging cells called nematocysts (or cnida), which are used to capture prey or repel predators, and some can cause severe reactions in humans.
True Jellyfish (Class: Scyphozoa)
Scyphozoans are widespread throughout the world’s oceans, from the colder waters of the Arctic and Antarctic to the tropics, where they propel themselves through the water by contracting and relaxing the muscles of the bell. Most live in shallow water around the coasts, but some inhabit deeper oceans. As with the other 3 classes that make up the phylum Cnidaria (the Anthozoans, Cubozoans and Hydrozoans), the scyphozoans have stinging cells (nematocysts) which are used for hunting prey and defence against predators.
Follow the order links below to the individual species fact sheets: