What is "aplysiidae"

The superfamily Aplysioidea is a superfamily of mostly rather large sea slugs, marine gastropod mollusks in the clade Aplysiomorpha within the informal group Opisthobranchia.

This superfamily contains only one family, the Aplysiidae; the sea hares. These animals are commonly called sea hares because, unlike most sea slugs, they are often quite large, and when they are underwater, their rounded body shape and the long rhinophores on their heads mean that their overall shape resembles that of a sitting rabbit or hare.

Sea hares are however shell-less sea snails, and some species are extremely large. The Californian black sea hare, Aplysia vaccaria is arguably the largest living gastropod species, and is certainly the largest living shell-less gastropod. In Australia sea hares are sometimes known as "beach blobbies". Sea hares do sometimes become stranded on beaches, and when this happens, they contract as much as possible to minimize desiccation, and when the sea hare's body is not fully supported by water, the rhinophores collapse and the animal looks more blob-like.