Within the genus Felimare there are 44 different species. One of them, Felimare tricolor, is a collorfull nudibranch belonging to the phylum Mollusca, class Gastropoda, order Nudibranchia, family Chromodorididae and genus Felimare. This species is distributed along the coasts of the eastern Atlantic Ocean and western Mediterranean Sea. It is a relatively common species that inhabits rocky bottoms from shallow water to 100 meters depth.
The body of Felimare tricolor can reach 2-3 cm in length and has an elongated shape with a dark blue base color. Centrally, running from the height of the rhinophores to the border of the gills and reaching the back of the dorsal part, we find a relatively wide white line in juveniles and more yellowish in adults. A thin yellow line runs along the entire margin of the mantle. In the anterior dorsal part, we find the lamellated rhinophores whose ends have a very dark blue color and the tip is slightly lighter. In the rear dorsal part we find a group of gills forming a circle that borders the anal opening. The gills, composed of 8 to 10 gill blades, are blue with a thin yellow/whitish central line that runs the entire length. The foot is blue with some white or yellow dots on the sides.
Felimare tricolor feeds exclusively on the sponges Dysidea avara and Dysidea fragilis, from which they are able to isolate certain compounds such as longifolin, which they use defensively by expelling them to the outside when they feel attacked.
Felimare tricolor is a hermaphrodite species. During the breeding season, the specimens lay thousands of small white eggs, contained in a spiral of about 3 turns.
Felimare tricolor is often confused with other closely related species. Felimare fontandraui differs in that the yellow-whitish central line begins in front of the rhinophores and adopts a 'T' shape, the rhinophores are uniformly blue. Felimare villafranca has unmistakable irregular stripes running longitudinally, the rhinophores are blue with a white stripe posteriorly. Felimare orsinii, probably the species most easily confused with Felimare tricolor, has a very thin white longitudinal stripe in the central dorsal part, the dorsal surface has small tubercles, and both rhinophores and gills are completely blue.Photos: