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Sea urchins

Echinoidea

There are more than 1,000 known species of sea urchin. They live in all the world’s oceans – from the tropics to the polar regions.

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Like starfish and brittle stars, sea urchins belong to the phylum Echinodermata. Most species of sea urchin therefore have a multitude of spines to defend themselves against predators, such as crustaceans, fish, starfish and sea otters. The spines of some species of sea urchin are also poisonous.

Furthermore, the spaces between the spines of large sea urchins provide a safe haven for smaller species.

Taxonomy

Echinoderms (Echinodermata), Eleutherozoans (Eleutherozoa)

Habitat

worldwide, in all oceans, down to a depth of 6,000 metres

Body length

The hard calcareous internal skeleton can usually be up to 10 cm in diameter. The largest species of sea urchin can reach a diameter of up to 36 cm.

Diet

algae, carrion, and occasionally smaller organisms

Taxonomy

Echinoderms (Echinodermata), Eleutherozoans (Eleutherozoa)

Habitat

worldwide, in all oceans, down to a depth of 6,000 metres

Body length

The hard calcareous internal skeleton can usually be up to 10 cm in diameter. The largest species of sea urchin can reach a diameter of up to 36 cm.

Diet

algae, carrion, and occasionally smaller organisms

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