Greenland and Baltic south to Canarias, Azores and Mediterranean. Grazer in the upper infralittoral, often in intertidal grounds. Gregarious when mating. Original taxon: Laplysia punctata. Many synonyms: albopunctata, guttata, hybrida, longicornis, marginata, nigromarginata, rosea, stellata, unicolor, virescens… and also varians, which is a relevant epithet for such a variable species.

Animals « similar to the slugs; their body is oval, flattened underneath to form a long, narrow foot, bulging above, more or less pointed behind, and narrowing a little forward in a kind of neck, susceptible of several degrees of elongation, and at the end of which is the head. […] Between [the edges of the sole], there is an almost semicircular piece attached by its left side only, mobile in its entirety as a hinged lid and whose edge, flexible at the whim of the animal, often forms a kind of gutter or half-channel suitable for driving water to the gills. The gills are, indeed, under this cover. – G. Cuvier: “Sur le genre Laplysia, vulgairement nommé Lièvre Marin”, Annales du Muséum d’Histoire Naturelle vol. XXVIII, Paris 1803, p.292.

It has been demonstrated that mediterranean specimens of Aplysia parvula are actually true punctata; cf. Golestani & al.: “The little Aplysia coming of age…”, Zoological Journal of the Linnean Society vol.187(2), London 2019, p40 of the PDF.