Description: This is the largest Aeolid in the British Isles. It is usually grey in overall appearance due to freckles of grey or brown pigment, but the colour is very variable. There is usually a V-shaped white mark on the front of the head with its base between the rhinophores and arms running out to the oral tentacles. The oral tentacles and rhinophores are tapering with thick bases. The cerata are somewhat flattened.

Habitat: Aeolidia feeds on sea anemones, taking a wide variety of species. In the intertidal the normal prey is Actinia equina, though Anemonia viridis and Metridium senile are also taken. In the sublittoral Actinothoe sphyrodeta is commonly eaten. The spawn is distinctive, consisting of a thread coiled back and forth and laid in a spiral.

Distribution: This is a widespread animal, occurring all round the British Isles and around Northern Europe as well as on the American Atlantic and Pacific coasts. It has been reported from Atlantic Spain and France, but appears to be more common in colder waters.

Key Identification Features:

• Large Aeolid with superficial pigment over body and cerata.
• Usually has a white V on front of head.