Flabellina affinis is an aeolid nudibranch found in the Atlantic from Portugal to Ghana and throughout the Mediterranean, at depths up to 50 m. Growing up to 50 mm, it primarily feeds on Eudendrium hydroids. It is often mistaken for Paraflabellina ischitana but can be distinguished by its cerata, which are opaque violet beneath the subapical white ring, unlike the translucent cerata of P. ischitana.

Paraflabellina ischitana is a vibrant aeolid nudibranch from the family Flabellinidae, predominantly found in the Mediterranean, particularly around Ischia and the Costa Brava. It thrives in shallow waters but can be found at depths up to 35 m. Reaching up to 4 cm, this species is characterized by its purple-violet body, white-tipped cerata, rhinophores, and oral tentacles. The cerata are translucent, revealing red-orange branches of the digestive gland. It is often mistaken for Flabellina affinis and Edmundsella pedata but can be distinguished by its annulate rhinophores and the lack of purple-violet coloration on its cerata.

Felimare villafranca is a striking dorid nudibranch from the family Chromodorididae, found in the Eastern Atlantic and the Mediterranean, ranging from France and the Bay of Biscay to Morocco, Cape Verde, the Canary Islands, and the Azores. It is primarily dark blue with intricate yellow lines that form patterns and networks across its mantle. The edge of the mantle features a double yellow line interspersed with bright blue patches or broken lines. The rhinophores and gills are translucent blue with white accents. This species can grow up to 40 mm in length.

Felimare orsinii is a colorful dorid nudibranch in the family Chromodorididae, found in the Western Mediterranean Sea. This species is identified by its entirely blue gills and rhinophores, small raised tubercles on its back, and distinctive white lines on its mantle, with the side lines grading into yellow. It grows up to 20 mm and feeds on the sponge Scalarispongia scalaris. Initially classified as Hypselodoris orsinii, it was reclassified to Felimare in 2012.

Felimida purpurea is a vibrant dorid nudibranch from the family Chromodorididae. Found in the Mediterranean and along the Atlantic coasts from the Bay of Biscay to Cape Verde and the Azores, it has a white to pale purple mantle edged with orange-yellow and embedded white mantle glands. Its rhinophores and gills are purple-pink with white tips. Growing to 35-50 mm, this species was reclassified from Chromodoris to Felimida based on DNA analysis.

Cratena peregrina, also known as the pilgrim hervia, is a slender aeolid nudibranch reaching 3-5 cm in length. It features a milky white body with 8 to 10 clusters of colorful cerata in shades of red, purple, brown, or blue, tipped with luminescent blue. The head bears bright orange rhinophores and two long, whitish buccal tentacles resembling horns.

Peltodoris atromaculata, also known as the dotted sea slug or sea cow, is a dorid nudibranch in the family Discodorididae, primarily found in the Mediterranean Sea and occasionally in the Atlantic from the Bay of Biscay to the Azores. Living at depths up to 40 m, it thrives in coralligenous habitats. This species is most abundant from June to September but can be seen year-round. It features a white mantle with randomly distributed brown spots, which are darker and more concentrated towards the center. Variations in spot density increase from west to east across its range. There is ongoing debate about its classification, with some studies suggesting it may deserve its own genus.

Calmella cavolini is a small aeolid nudibranch, growing up to 12 mm. It features smooth, elongated rhinophores, oral tentacles, and distinct angular corners on its anterior foot. Its cerata are grouped with bright red digestive glands and white-tipped cnidosacs. The jaw plates appear as reddish spots on each side of its head. It feeds on the hydroid Eudendrium. This species is found in the Mediterranean Sea and the North Atlantic near Spain and Portugal.

Description goesFelimare cantabrica is a striking dorid nudibranch in the family Chromodorididae, predominantly found in the Mediterranean Sea, including near Malta. It exhibits a vivid light and dark blue body adorned with yellow lines and spots, and a distinct yellow-light blue-yellow banded mantle edge. The gills and rhinophores are purple. This species reaches lengths of at least 40 mm and is known to feed on sponges, particularly those from the genus Dysidea.