Illustrated species account of Thecacera pennigera (Montagu, 1813) Mollusca, Nudibranchia. right) https://flic.kr/p/DzPeXL Body smooth with no ridges. Translucent white revealing central pale-buff viscera. Body and all appendages covered in orange, black

The nudibranch is one of the most colorful gastropod species found in oceans worldwide. Unlike many other gastropod groups, the nudibranch loses an external shell in the adult stage, but instead develops various chemical defense systems. More than 2,500

This work presents refined, updated subregional and regional non-indigenous species (NIS) inventories for the Mediterranean Sea, validated by national and taxonomic experts, with species records observed until December 2020. These datasets will be used