Specimens of the clam Panopea globosa were collected in the Gulf of California, Mexico in 2009. Tiny crabs were found living inside the clam, being Pinnaxodes gigas. Since both the description and the scarce subsequent reports of P. gigas were performed only from single free-living specimens, this is the first record of P. gigas associated as a symbiont of any host. This is also the first record of any geoduck clams as host of commensal crustaceans, and the second record of a pea crab of the genus Pinnaxodes encountered infesting bivalves in the Pacific.
