Description
Cancer gracilis caught off the coast of southern California. This picture was taken by Dave Pena
Date 21 June 2006 (original upload date)
Source: https://commons.wikimedia.org/wiki/File:Cancergracilis.jpg

Metacarcinus gracilis (formerly Cancer gracilis) or commonly the graceful rock crab or slender crab, is one of only two members of the genus Metacarcinus whose chelae (claws) are white tipped, the other crab being M. magister (Dungeness crab). M. gracilis has been caught from Alaska to Bahía Magdelena, Baja California. Larvae and small juveniles of this species are often seen riding jellyfish, especially Phacellophora camtschatica. The juvenile crabs steal food from the jellyfish and also clean off parasitic amphipods. Order: Decapoda, Infraorder: Brachyura, Family: Cancridae, Genus: Metacarcinus, Species: Metacarcinus gracilis (Dana, 1852), Synonyms: Cancer gracilis Dana, 1852.