Rubramoena rubescens
Rubramoena rubescens is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusk in the family Fionidae. Distribution. This species was described from St. John's Point, Dunkineely, Co Donegal, Ireland. It has been reported from the NE Atlantic from Norway south to Cornwall. Description. The typical adult size of this species is 12–15 mm. It is very similar to "Rubramoena amoena", apart from differences in the colour pattern. Habitat. "Cuthona rubescens" feeds on hydroids of the genus "Halecium" especially "Halecium halecinum".