Sars M., 1829
Description:
The ground colour of the elongated body (up to 29 mm), is olive green with white or yellow tubercles and papillae. The lamellate rhinophores and the tripinnate gills (up to five in number) are translucent brown, and the other conspicuous processes, the dorsal and lateral tubercles and the frontal papillae, are pale yellow. Especially obvious are the whitish compound papillae situated on either side of the branchial circlet, and the median longitudinal, dorsal metapodial papillae. The pedal sole and the flattened oral lobes are paler in colour. The general texture of the body is, compared with Polycera notha , more flaccid and less opaque.
Habitat:
This species is especially common sublittorally, from 10 to 100 m. The diet consists principally of the bryozoa Eucratea loricata .
Distribution:
Distributional records are confused because of merging with Polycera notha in the past. Certainly both species occur all around the British Isles, although P. dubia may be less common, preferring offshore habitats (Distr. P. dubia). Also reported off Helgoland (Harms, 1993).