What does "univalve" mean?

Univalve: A shell consisting of one valve only; a mollusk whose shell is composed of a single piece, as the snails and conchs. Note: Most univalves are spiral and are the shells of gastropods, but many belong to cephalopods and pteropods. A large number of univalves belonging to the gastropods are conical, cup-shaped, or shieldlike, as the limpets.

Additional senses

  1. 2.Having one valve; as, a univalve shell or pericarp.

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