Anthozoa facts for kids

Quick facts for kids Anthozoa Temporal range: late Ediacaran to present
Stony corals
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Anthozoa
Subclass:	Ceriantharia Hexacorallia Octocorallia

A stony coral in its natural habitat

Giant green anemone, Southern California

Anthozoa is a group of amazing sea animals that includes sea anemones and corals. They are part of a larger family called Cnidaria, which also includes jellyfish. Unlike jellyfish, Anthozoa do not have a free-swimming "medusa" stage in their life. Instead, they spend their lives as polyps, which are like small sacs attached to the seafloor or other surfaces.

Just like all Cnidaria, Anthozoa use special stinging cells called nematocysts to catch their food and protect themselves. These cells are very effective! Scientists have found and described over 6,100 different kinds of Anthozoa.

Types of Anthozoa: Subclasses

Anthozoa are divided into three main groups, called subclasses. Each group has its own unique features.

Ceriantharia: Tube-Dwelling Anemones

This group includes the tube-dwelling anemones, also known as cerianthids. These animals live inside long, soft tubes that they build in the sand or mud. They can pull themselves completely into their tubes if they feel threatened.

Hexacorallia: Six-Fold Symmetry

The Hexacorallia group is very large, with about 4,300 species. Most of these animals live in colonies, meaning many tiny polyps live together as one organism. Their bodies usually have a six-fold symmetry, meaning they can be divided into six equal parts around a central point.

• Stony Corals: This group includes all the stony corals. These corals are super important because they build the huge structures we call coral reefs. Coral reefs are like underwater cities that provide homes and food for countless other sea creatures.
• Sea Anemones: All sea anemones are also part of Hexacorallia. Sea anemones look a bit like colorful flowers, but they are animals that use their tentacles to catch small fish and other prey.

Octocorallia: Eight-Fold Symmetry

The Octocorallia group has about 3,000 species. Like Hexacorallia, these animals also live in colonies. However, their polyps have an eight-fold symmetry, meaning they have eight tentacles and eight internal divisions.

• Soft Corals: This group includes the blue coral and many soft corals. Unlike stony corals, soft corals do not build hard, stony skeletons. They are often flexible and sway with the ocean currents.
• Sea Pens: Sea pens look like old-fashioned quill pens stuck in the seafloor.
• Gorgonians: This group includes gorgonians, which are also known as sea fans and sea whips. They often grow in beautiful, branching shapes.

Images for kids

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  Deep water corals serve as habitats for fish such as the alfonsino

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  Anatomy of a stony coral polyp

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  Giant green anemone, a zooxanthellate species; the tentacles are armed with nematocysts to catch prey

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  White black coral Leiopathes glaberrima with white sea anemones below, both azooxanthellate, deep water species

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  Pocillopora damicornis produces yolky eggs and the planula larvae disperse widely.

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  Biodiverse, multi-coloured habitat

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  Dardanus calidus with Calliactis parasitica

See also

In Spanish: Antozoos para niños