About Ancula pacifica MacFarland, 1905
Ancula pacifica MacFarland, 1905 is a species of goniodorid nudibranch. The body of this nudibranch is translucent white, marked with orange lines. It has a mid-dorsal orange line and orange lines along the pallial margin; these lines may be either continuous or interrupted. The pre-rhinophoral papillae and gills have orange tips, and an orange pigment line runs along the ridge of the tail. This species has between 4 and 14 club-shaped extra-branchial papillae, which are translucent white with orange or yellow tips. Small papillae with orange tips typically appear between larger papillae that have pale yellow tips. In some populations, individuals can be found that lack the characteristic orange lines on the body. While Ancula pacifica is currently classified as a synonym of the European species Ancula gibbosa, it shows clear differences in the color and shape of its extra-branchial papillae, and it is likely a distinct species. This species was first described from specimens collected in Monterey Bay, California. Ecologically, Ancula pacifica is thought to feed on Entoprocta, a group of animals that commonly grow on hydroids, bryozoa, and other living substrates.
