The Black Longspine Sea Urchin (Diadema setosum) is a marine (saltwater) invertebrate echinoderm in the Diadematidae family. It is related to the Starfish (Sea star).
The Black Longspine Sea Urchin has extremely long, narrow, hollow spines that are mildly venomous. It has a hard, spherical (ball-shaped) shell, called a test. On its spherical body are five white dots. It does not have eyes. It is sensitive to touch, light, and chemicals, due to the numerous sense cells around its mouth.

It grows to about 7 centimetres (3 inches) in length.
It is found in the Indian Ocean and the Pacific Ocean, around the coasts of Australia to Africa to Japan and the Red Sea. It prefers to live in coral reefs, sand flats, and seagrass beds. It is benthic, living on the sea floor.
It can move, but very slowly. It often moves in a faster rolling motion.
The Black Longspine Sea Urchin feeds on algae. Its predators include otters, starfish, eels, and fish.
There are male and female Black Longspine Sea Urchins. The female lays about 200 eggs.
The lifespan of the Black Longspine Sea Urchin is about 20 years.

Location of photographs: Aquarium de Paris-Cinéaqua, France
Photographer: Martina Nicolls
Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM