This scallop has both valves
convex, sometimes attaches by byssal threads but does not cement a
to the rock, has no purple blotch inside the hinge, has 20-30 prominent
ribs on each valve but these ribs do not have prominent, rough spines
ruffles (it may have microscopic ones). It grows up to about
7) cm long. Anterior hinge wing (auricle) is usually about 2x
than the posterior one (according to some references and to the photos
below; other references say it is the posterior wing which is
When at rest on the bottom, the left valve is usually
valve exterior is pink, red-purple, white, or yellow; right (lower)
is usually paler (photo).
Chlamys (Chlamys) rubida (Hinds,
Common name(s): Smooth pink scallop,
Reddish scallop, Pacific
pink scallop, Swimming scallop
Chlamys hindsii, Chlamys
jordani, Chlamys rubidus
|Chlamys rubida, 5 cm width, captured
subtidally off Sares head
|(Photo by: Dave Cowles,
How to Distinguish from
Similar Species: Chlamys
hastata is about the same size and shape, but has
or spines on the ribs.
Geographical Range: Alaska
to San Diego, CA; uncommon S of Puget Sound.
Depth Range: Low
intertidal to 300 m; mainly
rocky or soft bottoms; most
common on gravel/mud bottoms.
This species has
a slower growth rate than does Chlamys
hastata, and puts less of its energy into
southern BC, individuals live about 6 years. These species of
have many eyes around the perimeter, which can perceive light and
but cannot form an image. Predators include the seastars Crossaster
papposus and Pycnopodia
helianthoides. Swimming is a primary
The sinuous whelk, Buccinum plectrum, may also be a
the presence of the whelk elicits a swimming response in the
May be parasitized by Odostomia columbiana, the
Clam Sucker snail.
This species of scallop is often covered with the symbiotic
incrustans or Mycale
adhaerens. The symbiosis is likely
one of the major predators of the scallop, Evasterias
troschelii, encounters the scallop (and the scallop
does not swim
away) it often turns away if it touches the sponge; likely in response
to some secretion or to the spicules from the sponge. The
also appears to make it more difficult for the seastar's tube feet to
to the scallop. If the sponge is removed from the scallop and
scallop is prevented from swimming, it is readily captured by the
The scallop will also swim from predators of the sponge, such as Archidoris
spp, so the sponge is benefited as well. The swimming scallop
also help carry the sponge into areas with clean water and good
nd help prevent fouling of the sponge.
and O'Clair, 1998
Burns, D. and B. Bingham, 2002. Epibiotic sponges on the
Chlamys hastata and Chlamys rubida:
in a high-sediment environment. J. Mar. Biol. Assn. U.K. 82:
General Notes and
Observations: Locations, abundances,
Can be found at Sares Head, but usually in much less abundance
is Chlamys hastata.
common in deep benthic trawls in the San Juan Channel.
When these scallops are kept in running seawater tanks the
sponges die and slough off within a few weeks. The scallops
Most individuals are at least partly encrusted with sponges,
in the same area are not.
Here is a view of the right valve of the individual above.
animals usually sit on the bottom with the left valve up and the right
The larger "wing" at the hinge projects anteriorly, and if the shell
is agape the foot can be seen near the anterior end of the shell.
|Here is a closeup of the left valve from the individual
Note that although there are many ridges they are almost entirely
||A closeup of the right valve of the same individual.
This individual is agape and its row of eyes along the edge of the
mantle can be clearly seen.
Another specimen of Chlamys rubida, from deeper
water (120 m,
San Juan Channel. Left valve shown. Photo by Dave
Some very tiny serrations appear to be present on the ridges, but a
closer view (below) shows them to be simply undulations of the
individual has the many ridges characteristic of C. rubida
am assuming that it is that species and not C.
hastata even though the ridges are not completely
The left valve (above, on top of the animal when it is sitting
is darker red than the right valve (below, next to the sediment when
animal is sitting normally).
Photo by Dave Cowles, July 2005, of an individual from 120 m depth
in San Juan Channel
Authors and Editors of Page:
Dave Cowles (2005): Created original page