To 15 cm across the test (body)
Reddish brown, occasionally white body, densly covered with short white spines. (usually evenly distributed but occasionally in clusters along joints of body plates).
A shallow water species, usually on sea grass beds and sand, but also on shallow reefs/ roc from 1-30ft (0.3-10m). Often covered with seagrass blades and other debris. 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. Young sea urchins conceal themselves in crevices and under rocks during the day but larger individuals stay out in the open. Feeds on soft algae, mostly at night.
Breeding probably takes place mostly in the summer. Male and female urchins liberate gametes into the sea where fertilisation takes place. The eggs soon hatch into larvae which are planktonic. These develop through a number of larval stages over the course of about one month before settling on the seabed and undergoing metamorphosis into juveniles. During their first year, young urchins increase their diameter by about 7 millimetres (0.28 in) a month. Growth rates slow down thereafter and growth halting completely after maturity was reached while the gonads were ripen. After liberation of the gametes, growth begins again.
| Ecological Descriptors
West Indian Sea Egg
White Sea Urchin
White Sea Egg