Bivalves

Delectopecten vancouverensis (Whiteaves, 1893)
Vancouver Scallop
subtidal, 27 - 4100m size to 45mm
northern Mexico to southern Alaska and northern Japan to Kamchatka
The shell is colorless and translucent with imbricated sculpturing. Smooth specimens are sometimes referred to as D. tillamookensis.
(synonym - Pecten randolphi)

Chlamys hastata (Sowerby, 1842)
Spiny Pink Scallop
intertidal to150m southern California to northern Alaska size to 83mm
Tiny live juveniles can be occasionally seen in tidepools, otherwise the occasional single adult valve may wash ashore. The upper shell is usually pink with some white radial streaks and the lower shell is pale. The ribs are raised and covered in sharp spines, particularly in the specimens found south of Puget Sound. An alternate name, Chlamys h. hericia, is sometimes used to describe specimens north of Washington which tend to have more subdued ribs. These geographic subspecies are then referred to as Chlamys hastata hastata (Sowerby, 1842) and Chlamys hastata hericia (Gould, 1850). The color can occasionally be shades of yellow to orangish and infrequently, white. Live specimens are frequently covered with sponge growth.

Puget Sound, WA Dixon Entrance, BC, juvenile San Juan Islands, WA, subtidal

Patinopecten caurinus (Gould, 1850)
Weathervane Scallop or Giant Pacific Scallop
subtidal, 10-300m central California to northern Alaska size to 30cm
The shell is thin for its size. It starts out pink to red and becomes more tan with age. The shell can become as large as a dinner plate.

Crassadoma gigantea (Gray, 1825)
Purple-hinged or Giant Rock Scallop
intertidal to 80m northern Mexico to northern Alaska size to 25cm
This can be found at very low tides, both in the juvenile swimming form and as an adult attached the undersides of rocks. The juveniles can be mistaken for the Chlamys species. The rock scallop juveniles tend to be yellow or orange, while the Chlamys juveniles tend to be pinkish, although all the species can be a range of colors. The rock scallop juvenile is also wider and has more robust sculpturing. The purple stain on the interior of the hinge is very distinctive and is present even in the juveniles. The older adult specimens are generally heavily encrusted and come to resemble the rocks.
(synonyms - Hinnites giganteus, Hinnites multirugosus, Chlamys gigantea)

Unalaska Island, AK
Parvamussium alaskense (Dall, 1871)
Alaska Glass-Scallop
subtidal, 15-1530m size to 25mm
southern California to northern Alaska; Bering Sea to northern Japan
This fragile shell has closely spaced commarginal ribs. The right valve is smaller than the left.
(previous name - Pecten alaskensis)

San Juan Islands, WA color variations

Chlamys rubida (Hinds, 1845)
Smooth Pink Scallop
subtidal, 1-200m size to 70mm
southern California to northern Alaska and west to northern Japan (not common south of Puget Sound, Washington)
Tiny live juveniles can infrequently be found at water's edge during a low tide. The upper valve of the shell is pink to reddish-purple, occasionally yellow to orange, and infrequently, white. The radial ribs are smooth. The lower valve is pale. The live shells are often encrusted with sponge. Those specimens in the more northern range with coarser sculpture were once called Chlamys hindsii. More southern specimens with stronger microstructure and brighter colors were once called Chlamys jordani.

Propeamussiidae

well offshore, central BC coast
Cyclopecten davidsoni (Dall, 1897)
Salmon Glass-Scallop
subtidal, 146-650m size to 15mm
north Oregon to south Bering Sea
The left valve is usually a salmon color.
(previous name - Propeamussium davidsoni, Pecten davidsoni)

Family Pectinidae & Propeamussidae