We saw this large nudibranch on a number of occasions, usually at night at Makua and Pupukea, and once during the day at the Halona Point Blowhole on Oahu. These Hawaiian specimens are similar to, but not quite the same as the animals we are calling Platydoris formosa in the Marshall Islands. This is another species that could probably use a bit more study.
Links:
Sea
Slugs of Hawaii
Sea
Slug Forum
Marshall Islands Sea Slugs
Created 20 April 2009