Ancula gibbosa Risso, 1818 Ancula pacifica is a species of sea slugs, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.
This goniodorid nudibranch is translucent white in color with orange lines on the body.
There are 4-14 club-shaped extra-branchial papillae which are translucent white with orange or yellow tips.
Although currently considered to be a synonym of the European species Ancula gibbosa there are significant differences in color and shape of the extra-branchial papillae and this is probably a distinct species.
Ancula pacifica probably feeds on Entoprocta which often grow on hydroids, bryozoa and other living substrata.