The West Indian sea egg is a tropical sea urchin found in shallow coastal waters of the western Atlantic ocean. Discreet yet abundant in seagrass beds and on reefs, it plays an important role in maintaining coastal ecosystem balance by grazing on algae and recycling organic matter.

The West Indian sea egg is a nearly spherical echinoderm, with a test that can reach about 4 to 6 inches in diameter. Its color ranges from dark brown to purple, contrasting with its typically white, short and fine spines.

It can sometimes cover itself with debris such as pieces of algae or shell fragments, which it holds using its tube feet, providing camouflage and protection against strong light.

The West Indian sea egg is found in the tropical western Atlantic, including the Caribbean such as Guadeloupe, the Gulf of Mexico, the Bahamas, and as far as the coast of Brazil.

The West Indian sea egg mainly lives in seagrass beds, sandy areas rich in vegetation, and shallow coral reefs. It is generally found down to depths of about 180 ft, but most often remains in very shallow waters where light supports the growth of the algae it feeds on.

The West Indian sea egg is an opportunistic herbivore that primarily feeds on algae and seagrass vegetation. It may also ingest decomposing organic matter. By grazing on algae, it helps maintain the balance of reefs and seagrass ecosystems.

The West Indian sea egg reproduces sexually through external fertilization. Males and females release their gametes into the water, where fertilization occurs. The larvae then develop in the plankton for several weeks before settling on the seabed and transforming into juvenile sea urchins.