We found this small species only a few times, at Makua, Makua Ledge and Pupukea on Oahu. The Sea Slugs of Hawaii site, where it is listed as Noumea sp. 4, notes that it is moderately rare but still seen occasionally. Our first specimen, figured in the first two photos below, was in a cave at night off Pupukea on 22 March 1978. It was apparently eating the grayish sponge it is resting on. This species is similar in color to Noumea varians.
Our second specimen was found during a day dive off the Makua Ledge, Oahu, on 11 July 1979.
Links:
Sea
Slugs of Hawaii
Sea
Slug Forum
Created 20 April 2009