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Long-spined Urchin Diadema antillarum


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Long-spined Urchin
credit: Dpbsmith/CCSA

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Category: Seastars and relatives view all from this category

Description Diadema antillarum, also known as the lime urchin, black sea urchin or the long-spined sea urchin, is a species of sea urchin in the Family Diadematidae.

This sea urchin is characterized by its exceptionally long black spines.

It is the most abundant and important herbivore on the coral reefs of the western Atlantic and Caribbean basin. When the population of these sea urchins is at a healthy level, they are the main grazers which prevent algae overgrowth of the reef.

Diadema antillarum has a test, or "shell," similar to most other sea urchins. What distinguishes the Diadema is the length of its spines. Most sea urchin spines are 1-3 cm, but the spines in this species are usually 10-12 cm in length, and can grow as long as 30 cm in very large individuals.

Warning Bathers and divers in the American tropics know and respect the long, sharp spines of this urchin, which can puncture a wetsuit or tennis shoe and cause intense irritation if lodged in the skin.

Habitat Coral reefs.

Range Florida.