Atlantic Bay Scallop

Common Name

Atlantic Bay Scallop
Scientific Name
Argopecten irradians
The shell of the Atlantic Bay Scallop reaches 6 - 7 cm in length and is characterized by having two nearly identical fan-shaped shells. The shell colour is typically in the brown to grey range. There are four distinct sub species:  
1) A. irradians irradians has 17-18 ribs and can be found from the North shore of Cape Cod to New Jersey.
2) A. irradians concentricus has 19-20 ribs and can be found from Maryland to Georgia and Louisiana to Tampa. It is also rarely found in Jersey. 
3) A. irradians amplicostatus has 12-17 ribs and can be found from central Texas to Mexico and Colombia.
4) A. irradians sablensis has 18-21 ribs and is an extinct species. Valves can be found on Sable Island dating to times of warmer waters (1800 years ago).
Above is a picture of a live Atlantic Bay Scallop (
Above is a photo of an Atlantic Bay Scallop shell (credit: Project UFO). 
General Geographic Range
The Atlantic bay scallop (Argopecten irradians) is found in parts of Nova Scotia (warmer waters) to the northern half of Florida and Texas.
The Atlantic Bay Scallop lives in coastal marine environments where seagrass meadows are common.   They are likely to be found in habitats covered with eel grass (Zostera marina) and/or shoal grass (Halodule wrightii). They are most commonly found in calm waters 0.3 to 0.6 meters at low tide.
Scallops feed by filter-feeding; they typically trap and ingesting floating dead and decomposing plant and animal matter.
Introduction History
Live Atlantic Bay Scallops have been found outside the reported native range.  There have been reported live sightings along the coast near Cheticamp (Gretchen Noyes-Hull, personal communication, 2008) and Lingan Bay, Cape Breton Island (Project UFO, 2008). Argopecten irradians shells have also been found at Dominion Beach and Big Glace Bay beach over the past two years. It is possible that the introduction of the Atlantic Bay Scallop into Cape Breton waters is a result of the aquaculture of this species. Several areas in Nova Scotia (unlike Cape Breton) have water temperatures warm enough to support the development of juvenile Atlantic Bay Scallops. It is possible that adult scallops have escaped from aquaculture captivity and have entered our waters.
Additional Websites
·        The New York State Department of Environmental Conservation website is a great source of information concerning the Atlantic Bay Scallop.
·        The Texas Parks and Wildlife website also features fun facts about the Atlantic Bay Scallop.