-50m, Trawled on mud and seaweed bottom, Japan Sea, Japan, 103.9mm., 2014/viii
The « Swift's Scallop » is a colourful and attractive medium-large pectinid distributed from Japan Sea to northeast Japan to Sakhalin, Russia. Although quite distinctively shaped, it is very variable in knobbiness depending on number of growth pauses the specimen has had, each pause forming a row of knobs. The colouration may differ from bright yellow to purple to red to dark brown, and it is very popular among collectors for this reason. In the most frequent colouration (shown), the left valve is a reddish purple and the right valve is white. A comrn.on filter-feeding bivalve, it inhabits mostly rock and gravel bottoms of shallow water from lowtide depths down to about -50m. Typical shell length around 80mm., very large specimens may exceed 120mm. It is considered a delicacy in the Japonic region, particularly Hokkaido where it is fished and eaten along with Mizuhopecten yessoensis (Jay, 1857).