Chromis, Midway, 40 feet

Laying eggs, Lanai Lookout, Oahu, 40 feet

Blowhole, Oahu, 30 feet

Kapalua, Maui

100 ft. Hole, Waikiki, Oahu, 80 feet

Juvenile, 100 ft. Hole, Waikiki, Oahu, 80 feet

Sea Cave, Oahu, 45 feet

YO-257 wreck, Oahu, 90 feet

Juvenile, Sea Tiger wreck, Oahu, 100 feet

LCU Wreck, Oahu, 75 feet

Makapu'u tidepool, Oahu

Lahilahi Point ,Oahu, 40 feet

Blowhole, Oahu, 30 feet

Common on hydroid-encrusted reefs and wrecks.  Rhinophores and tentacles with purple rings, body variable according to diet, in Hawaii typically blue to lilac, occasionally brown, white when very young.  Attains 5 inches.  Pteraeolidia ianthina was determined to be the East Australian member of this species complex.  Indo-Pacific, including Hawaii.