Identification: the test, rounded and somewhat flattened in adults, is purple, green or dull red blotched with white. Most spines are short (1 to 2 cm), with a few longer primary spines; their colour varies (green, brown, white, purple, pink, orange, red), often differing between base and tip. In the Caribbean the commonest combinations are a green test with green spines or a green test with white spines. Its pedicellariae are white, whereas those of the smaller related Lytechinus williamsi are purple. Several subspecies are recognised, including the more colourful L. v. carolinus, from North Carolina to the Gulf of Mexico.
In the wild it ranges from the United States to Brazil and throughout the Caribbean, from the surface to 50 m (rarely deeper), in seagrass beds, especially Thalassia, mangroves, sandy or muddy bottoms and under rocks; there can be up to 15 per square metre. It holds pieces of algae, seagrass and shell on its upper surface with its tube feet, which may shield it from sunlight and UV; in wave tanks, covered or aggregated urchins stayed put on the sand while the others rolled around. It is mostly herbivorous but can become omnivorous when needed.
Reproduction: the spawning period varies across its range; in Bermuda it is short and seems linked to the moon. Gametes are released into the water and the pluteus larvae live in the plankton before metamorphosis. It is a laboratory model organism and is farmed for food in Venezuela.
Status: it has not been evaluated by the IUCN and is not CITES-listed. It is uncommon in the aquarium trade.
