Flabellina affinis

Flabellina affinis is a species of sea slug within the clade of aeolid nudibranch; a marine gastropod mollusk in the family Flabellinidae.

Distribution
This species is found in depths to 50 m in European waters in the Atlantic Ocean from Portugal to Ghana and the Canaries and is widespread in the Mediterranean Sea.

Description
The species can grow to a length of 50 mm. It feeds primarily on species of Eudendrium, a very common hydroid genus in the Mediterranean Sea.

Flabellina affinis is often confused with Paraflabellina ischitana, but can be distinguished as follows:


 * Flabellina affinis: the outer part of the digestive gland in each ceras is not visible as the area beneath the subapical white ring is opaque violet in colour.
 * Paraflabellina ischitana: the ceratal surface has no purple-violet colouration and is translucent.