West Indian Sea Egg

The test of the West Indian sea egg is dark in color, usually black, dark purple or reddish brown, with white spines 1 to 2 centimetres (0.39 to 0.79 inches) long. The test can reach 10 to 15 centimetres (3.9 to 5.9 in) in diameter. It is often covered with pieces of seagrass, fragments of shell and other debris in a manner similar to the closely related Tripneustes gratilla. These decorations are held in place by tube feet among the spines and are believed to provide protection from the intense sunlight that penetrates the shallow water.

The West Indian sea egg is found in shallow parts of the western Atlantic Ocean, the Caribbean Sea and Gulf of Mexico. Its range extends from Bermuda, the Carolinas and Florida to Belize, Venezuela and Brazil and also includes the west coast of Africa and Ascension Island. It seldom occurs in water deeper than 10 metres (33 ft). It is found in seagrass meadows, in rubble areas and on shallow rocky reefs. Young sea urchins conceal themselves in crevices and under rocks during the day but larger individuals stay out in the open.