Nudibranchs belong to the order Nudibranchia, a group of soft-bodied marine gastropod molluscs that shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", and "sea rabbit". Currently, about 3,000 valid species of nudibranchs are known.
Image: Berghia coerulescens (Laurillard, 1830)
Image: Chromodoris lochi (AA3)
Glaucus atlanticus is an example of a nudibranch that has its cerata positioned like wings instead of on its back.
Nudibranchs (Nembrotha kubaryana) eating Clavelina tunicate colonies
Gastropods, commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda.
Gastropoda
Cepaea nemoralis: a European pulmonate land snail, which has been introduced to many other countries
The shell of Zonitoides nitidus, a small land snail, has dextral coiling, which is typical (but not universal) of gastropod shells.
The upper pair of tentacles on the head of Helix pomatia have eye spots, but the main sensory organs of the snail are sensory receptors for olfaction, situated in the epithelium of the tentacles.
