Snorkeler taking photo of urchin underwater off Maui, Hawaii, United States of America, Pacific

Pair of coleman shrimp on a red and yellow fire urchin, Bali, Indonesia.

Red (radiant) urchin (Astropyga radiata), close-up, Cars, Dumaguete, Negros Island, Philippines, Southeast Asia, Asia

Red pencil sea urchin (Heterocentrotus mammillatus), Molokini crater, Maui, Hawaii, United States of America, Pacific

Red pencil urchin, (Heterocentrotus mammilattus), Blowhole, Oahu, Hawaii, United States of America, Pacific

Long Spined Urchin. Red Sea.

Colony of white-spotted diadem Black Longspine Urchin sp (Diadema setosum) on seagrass meadow, Red Sea, Aqaba, Kingdom of Jordan

Peacock Collector Urchin (Tripneustes gratilla), Red Sea, Aqaba, Kingdom of Jordan

A Red Slate Pencil Urchin (Heterocentrotus mamillatus) rests on Molokini Backwall which is located offshore of Maui; Hawaii, United States of America

Surrounded by patches of Rice Coral (Montipora capitata), a Red Slate Pencil Urchin (Heterocentrotus mamillatus) and a Needle-spined (Urchin Echinostrephus aciculatus) rest on Molokini Backwall which is located offshore of Maui, Hawaii, USA; Molokini Crater, Maui, Hawaii, United States of America

Hawaii, Maui, Molokini, tropical reef scene with woman snorkeling variety of fish

Colourful coral reef and schooling fish, Hawaii, United States of America

Indonesia, Komodo Island, Two coleman shrimp (periclimenes colemani) on bright pink urchin.

Hawaii, slate pencil urchin, (heterocentrotus mammillatus).

Diadema sea urchin, Poor knights Island New Zealand