This pea crab has a hardened
less than 1.5x as wide as long, smooth or finely granulated.
borders of the carapace
are smoothly curved. Legs 3 and 4 do not have long hairs, and
of the walking legs are not strongly curved. The males of
have very large, thick claws for a pea crab, with a thick propodus
and a short, curved, toothed dactyl
claws of immature individuals
and of females are much smaller and slender, with nearly equal fingers,
small cutting teeth, and sharp tips. The cornea of the eye is
width of females to 12.9 mm, males slightly smaller. The
leg is the longest.
Common name(s): Burrow pea crab
a tubeworm burrow in Padilla Bay. Background ruler scale is
mm. Carapace dimensions for this male are 12 mm wide by 8 mm
|(Photo by: Dave
How to Distinguish
Mature males and females ofFabia
subquadrata have long hairs on legs 3 and 4,
plus the dactyls
of the walking legs are strongly curved. Most other pea crabs
at least 1.5x as wide as long.
British Columbia, Canada to Ensenada, Baja California, Mexico
Mid intertidal to
Commensal in burrows of
mudflat hosts such as Neotrypaea
pugettensis, and the fat inkeeper worm Urechis
caupo. Johnson and Snook say that the females of
live in mussels and other bivalves.
on detritus. Also filter feeds with its maxillipeds.
More than one crab may be commensal in the same burrow. The
elongata sometimes grows on the crab. In central
CA, mature females
are most abundant February to April but may be found from January to
and Fairbanks, 1966
and Snook, 1955
and Hanby, 2005
and McConnaughey, 1985
et al., 1985
General Notes and
abundances, unusual behaviors:
This closeup of the face and claw of the male shows the
the eye and the thick propodus
and curved dactyl
of the cheliped.
Authors and Editors of Page:
Dave Cowles (2009): Created original page
CSS coding for page developed by Jonathan Cowles (2007)