Blowhole, Oahu, 30 feet

Lanai Lookout, Oahu, 30 feet

Sharks Cove, Oahu, 25 feet

Juvenile, Kewalo, Oahu, 80 feet

Kewalo Hump, Oahu, 90 feet

Pokai Bay, Oahu, 15 feet

Mahi Wreck, Oahu, 80 feet

Uncommon at any depth basally attached to the substrate.  Easily identified by ragged margins.  Attains diameter of at least 12 inches.  Formerly abundant and harvested to near-extinction at Pearl Harbor and Pearl & Hermes Reef.  It is illegal to collect this species.  Endemic to Hawai'i.  Previously lumped within the Indo-West Pacific species Pinctada margaritifera.