DIRK WIERSMA / SCIENCE PHOTO LIBRARY DIRK WIERSMA / SCIENCE PHOTO LIBRARY
Heterocentrotus mamillatus, popularly known as the slate pencil urchin or red pencil urchin, is a species of tropical sea urchin indigenous to the Indo-Pacific region. It is large a sea urchin, it's test (the rigid, central body enclosing the internal organs) Â± 8 cm in diameter, from which the spikes radiate out up to 15 cm. The classical colour is bright red, but they can also be brown, or even purple. The elongate spikes are rounded in cross-section, and bluntly rounded at their tips. Their habitat is in offshore reefs and in shallow shoreline tidal pools. They remain in their underwater recesses and crannies during daytime, emerging at night to graze on algaeand other seaweed.
Model release not required. Property release not required.