Home > Invertebrates > Sea Urchins > Heterocentrotus mamillatus

Updated 2/6/2016

Family Echinometridae


Heterocentrotus mamillatus

Slate Pencil Urchin, Blowhole, 10 feet, 50mm

Blowhole, Oahu, Hawaii, 20 feet

Sea Cave, Oahu, 45 feet


Palea Point, Oahu, Hawaii, 25 feet


Lanai Lookout, Oahu, 35 feet

Kailua Bay, Hawaii, 20 feet


Kapoho tidepool, Hawaii


Ahihi Bay, Maui, 4 feet


Honokohau, Hawaii, 10 feet


Molokini Back Wall, 30 feet


Makapu'u, Oahu, 20 feet


Juvenile, Makapu'u, Oahu, 15 feet

Sea Cave, Oahu, 45 feet


Night, Lana'i Lookout, Oahu, 15 feet

Hanauma Bay, Oahu, 25 feet

Blowhole, Oahu, Hawaii, 20 feet


Locally abundant in clear shallow water.  Rare outside the Hawaiian Islands.  Spine shape variable.  Pale brown with light bands at night.  Overall diameter of 10 inches.  Hawaii & the Indo-Pacific.  The species name has long been spelled with two 'm's in the middle but only one 'm' is correct:  http://www.marinespecies.org/aphia.php?p=taxdetails&id=568045