Aldisa pikokai is not all that uncommon, but is not too easy to spot due to its cryptic appearance. Its external morphology, complete with crosshatching ridges and three dorsal crater-like depressions, makes it look very much like a kind of sponge rather than a nudibranch. A nocturnal species, we found these at night at Makua and Pupukea on Oahu and at Puako on Hawaii. The few found during the day were underneath rocks at depths of about 14m of Ewa, Oahu. We have seen what appear to be the same species in the Marshall Islands.
The nudibranch appears to eat an orange-red encrusting sponge.
Created 20 April 2009