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Who?
Family: Echinodermata
Species: Diadema antillarum
Species ID: E.DA
Description: A relatively large urchin with long black spines (1) a spherical test, or “shell” (2), and a small mouth located underneath the body (3). Spines are serrated and very brittle, easily breaking off in skin if accidently touched. Spines are occasionally white, and young urchins sometimes have banded spines
Maximum Size: 7.5 cm (3 in) test diameter excluding spines
Longevity: Up to 5 years
Status: Not currently on the IUCN endangered species list
Long-Spined Urchin & People: The gonads (reproductive tissue) of long-spined urchins are consumed on some Caribbean islands, but collection is small scale. The main importance of the long-spined urchin to fisheries is through the reduction of algae. Long-spined urchins help control algae growth, which in turn promotes coral growth. Longspined urchins were one of the greatest consumers of algae on Caribbean coral reefs, but in 1984 a pathogen killed 95% – one of the most severe die-offs ever recorded in the Caribbean. Algae cover subsequently increased between 100% and 250%
Where?
Geographical Range: Found throughout the Caribbean, Florida, Gulf of Mexico and south to Brazil, as well as along Africa’s west coat
Coral Reef Zone: Found in all coral reef zones
Favourite Habitat: Long-spined urchins are commonly found on hard reef substrate, but are also found on sand or in seagrass beds
Depth Range: 0–400 m (0–1312 ft)
A Day in The Life:
Dawn: Urchins seek shelter in shady crevices
Day: The day is spent hiding in reef cracks and crevices; limited feeding may occur
Dusk: Urchins leave their daytime shelters from about 3 P.M. onwards and begin feeding; spawning may also occur
Night: Urchins are most active between midnight and 3 A.M., when they graze on algae
Who Eats Who
Long-spined urchins eat most types of algae that grow on coral reefs and seagrass leaves, including red, green, brown, and blue-green algae. Its pedators include crabs, starfish, and fish such as grunts, porcupinefish, queen triggerfish and Spanish hogfish.
Scuba Diver & Snorkeler Best Practices
Take care with fins A careless fin stroke can break coral and stir up sediments that reduce visibility, which in turn can reduce photosynthesis and smother the reef.
