Felimare orsinii

Felimare orsinii is a colorful sea slug found in the Western Mediterranean Sea. This nudibranch can be recognized by its entirely blue gills and rhinophores, alongside small raised tubercles on its back. A distinct median white line edged with blue runs down its body, with a white mantle edge that transitions to yellow at the sides. The species typically reaches a length of 20 mm. In the Eastern Mediterranean, individuals may lack the yellow coloration but are still classified as the same species. It feeds primarily on the sponge Scalarispongia scalaris. Diving encounters with Felimare orsinii can be intriguing, as divers may spot this species in various habitats, including rocky reefs and sponge gardens. Observing its feeding behavior can be particularly interesting, as it grazes on its sponge diet. The nudibranch's colors and unique morphology make it a captivating sight for divers exploring the Mediterranean's underwater landscapes. Breeding behavior is not detailed in the sources, but nudibranchs are generally known for their hermaphroditic reproduction. The conservation status of Felimare orsinii is not evaluated in the sources. However, divers should always be mindful of their impact on fragile marine ecosystems, including the habitats of such nudibranchs.