Yellow Dorid - Baptodoris cinnabarina

In the stretch of sea between Cagliari and Villasimius, we encountered the Baptodoris cinnabarina, a yellow nudibranch once very common in the shallow waters of the Mediterranean Sea. The Yellow Dorid is an opisthobranch gastropod mollusk belonging to the order Nudibranchs, suborder Doridina. The immense family of Molluscs includes a wide variety of living organisms, all of which share five characteristics:
1) a head containing sensory receptors, a mouth, and a radula for scraping.
2) a visceral region containing the bloodstream, stomach, kidneys, and sexual organs.
3) a mantle surrounding the visceral region containing the gills (respiration), anus, and genital openings.
4) an internal or external shell, or sometimes just a remnant of a shell.
5) a foot that acts like a sucker for walking. doride giallo baptodoris cinnabarina

Gastropods are the class of mollusks with the largest number of species, some with robust shells (a single one, unlike bivalves), others with extremely small or completely absent shells. Opisthobranchs are gastropods with minimal shells, and in most species, none at all. Their name derives from the fact that they have gills for respiration located at the rear of their bodies. The name nudibranchs refers to organisms with naked gills. All species have abandoned shells and are equipped with cephalic appendages called rhinophores, which serve chemoreceptive and tactile sensory functions.

Like sacoglossans, they all have a radula, but they are not herbivorous, but exclusively carnivorous. Let’s delve into the nudibranch family by examining its most striking features:
< their movement is slow, creeping;
< swimming is absent or occasionally graceful and slow, produced by the movements of their various appendages;
< their coloration is bright, clearly standing out from the substrate, as if to warn a potential attacker of the stinging power of their appendages, whatever they may be.

http://www.biologiamarina.org/doride-giallo-cinnabarina/

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