Home > Invertebrates > Sea Urchins > Echinothrix diadema

Updated 8/8/2013

Family Diadematidae


Echinothrix diadema

Kahe Point, O‘ahu, 15 feet


Kaiwi Point, Hawaii, 4 feet

Juvenile, Kaunolu Bay tidepool, Lana'i


Kahe Point, O‘ahu, 15 feet

Spawning, Makapu‘u tidepool, O‘ahu


Makapu‘u tidepool, O‘ahu

Spawning, Ft. Kamehameha, O‘ahu, 3 feet



Juvenile, Makapu‘u tidepool, O‘ahu



Sea Cave, O‘ahu, 35 feet


Kahuku, O‘ahu

Makapu‘u Pinnacle, O‘ahu, 20 feet


Juvenile, Lana'i Lookout, Oahu, 15 feet

Juvenile, Kaunolu tidepool, Lana'i


Common in very shallow water exposed to wave action.  Stout blue-black primary spines protect venomous secondary spines which are banded with yellow and black, primary spines of juveniles banded.  Test diameter and spine length each attain 4 inches.  Gonads are delicacy.  Hawaii & the Indo-Pacific.