Sea urchin, Wikipedia

Sea urchin
Wikipedia.org

Ecology
Sea urchins feed mainly on algae, but can also feed on a wide range of invertebrates such as mussels, sponges, brittle stars and crinoids.[2] Sea urchin is one of the favorite foods of sea otters and are also the main source of nutrition for wolf eels. Left unchecked, urchins will devastate their environment, creating what biologists call an urchin barren, devoid of macroalgae and associated fauna.

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