(Forbes & Goodsir, 1839)
Description:
This variable, slender and aggressive aeolid may reach a length of 38 mm, with a translucent white body having a rosy blush over the mouth and a characteristic blue surface sheen over the dorsal side of the head. Both oral and rhinophoral tentacles exhibit chalk-white streaks. The cerata often show iridescent blue characteristics, combined with superficial chalk-white pigment extending irregularly down the frontal aspect. The digestive gland lobes vary in colour from pale brown to dark chocolate brown or blood-red. The whole aspect of the body is more slender than that of Facelina bostoniensis.
Habitat:
The largest collections of F. coronata have come from clumps of the hydroid Tubularia indivisa growing in water deeper than 15 m. In shallower water some specimens have been taken from Obelia spp. and Laomedea flexuosa attached to the fronds of Laminaria.
Distribution:
Records have come from localities all around the British Isles (Distr. F. coronata). Elsewhere its distribution extends from Norway to the Iberian Peninsula and the western Mediterranean Sea.