Limpet Snail ~ Several varieties

Class: Gastropoda

Limpet Snail is a common name for a variety of snails that grow a conical shaped shell. There are True Limpets and false limpets, some of which are the keyhole limpets. Limpets are mollusks. Mollusks are second in species diversity only to that of insects.

The common name "limpet" also is applied to a number of not very closely related groups of sea snails and freshwater snails (aquatic gastropod mollusks). Thus the common name "limpet" has very little taxonomic significance in and of itself; the name is applied not only to true limpets (the Patellogastropoda), but also to all snails that have a simple shell that is broadly conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snail. In other words, the shell of all limpets is "patelliform", which means the shell is shaped more or less like the shell of most true limpets. The term "false limpets" is used for some (but not all) of these other groups that have a conical shell. Thus, the name limpet is used to describe various extremely diverse groups of gastropods that have independently evolved a shell of the same basic shape (see convergent evolution). And although the name "limpet" is given on the basis of a limpet-like or "patelliform" shell, the several groups of snails that have a shell of this type are not at all closely related to one another.

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