About Flabellina affinis (Gmelin, 1791)
Flabellina affinis (Gmelin, 1791) is a species that can grow up to 50 millimeters in length. It feeds primarily on species from the genus Eudendrium, a very common hydroid genus native to the Mediterranean Sea. This species is often confused with Paraflabellina ischitana, but the two can be distinguished by key features of their cerata. For Flabellina affinis, the area beneath the subapical white ring on each ceras is opaque violet, so the outer part of the digestive gland inside each ceras is not visible. For Paraflabellina ischitana, the ceratal surface has no purple-violet colouration and is translucent. This species occurs at depths down to 50 meters. It is found in European Atlantic Ocean waters ranging from Portugal to Ghana, as well as around the Canaries, and it is widespread throughout the Mediterranean Sea.
