- a pea crab, Pinnotheres ostreum, the female of which lives as a commensal within the mantle cavity of oysters.
Origin of oyster crab
First recorded in 1750–60
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for oyster crab
The oyster-crab is a true messmate, and its presence in the oyster may be advantageous in helping to provide food for its host.The Sea-beach at Ebb-tide
Augusta Foote Arnold
- any of several small soft-bodied crabs of the genus Pinnotheres, esp P. ostreum, that live as commensals in the mantles of oysters