This Lithodid crab has a
hugely expanded carapace
so wide that it completely covers its walking legs unless the legs are
stretched out (picture).
is wider distally than it is proximally (picture).
of the chela
is smooth (picture).
The margins of the
abdominal plates do not have raised margins (picture).
Dorsal color variable--streaked gray like the specimen above, brown,
(some males), or olive. Underside of carapace is nearly
Small individuals may be white or light brown. Male carapace
Common name(s): Umbrella crab,
Turtle crab, Sitka crab
|Cryptolithodes sitchensis from
depth, Sares Head
|(Photo by: Dave
How to Distinguish
Similar Species: Cryptolithodes
typicus has a similar body shape but has a rostrum
that is widest
at the base, the propodus of its chela is rough, and the margins of its
abdominal plates have raised margins.
Bay, Alaska to
Point Loma (San Diego), CA
Depth Range: Intertidal
to 15 m
shores, usually on outer
coast. Nestles under rocks or in crevices in algae-covered
low intertidal and subtidal
This species, like
typicus, is very slow moving. Feeds on
algae such as Corallina,
Calliarthron, and Bossiella.
Tends to be found at shallower depths than C. typicus
and Carlton, 1975
and Laurent, 1979
et al., 1980
and O'Clair, 1993
General Notes and
Observations: Locations, abundances,
Cryptolithodes sitchensis rostrum is widest at
Cryptolithodes sitchensis underside.
that the propodus
of the chela is smooth, and that the abdominal plates do not have
margins. The underside of the carapace is nearly always
Photo by Dave Cowles, July 2001
Authors and Editors of Page:
Dave Cowles (2005): Created original page