Placopecten magellanicus, previously listed as Pecten tenuicostatus and as Pecten grandis and once referred to as the "giant scallop", common names Atlantic deep-sea scallop, deep sea scallop, North Atlantic sea scallop, American sea scallop, Atlantic sea scallop, or sea scallop, is a commercially important pectinid bivalve mollusk native to the northwest Atlantic Ocean. Description The shell has a classic form, with smooth shell and edges, unlike Pecten maximus (common name the "great scallop" or "king scallop") which has flutes and scalloped edges; size is around , with individuals up to in diameter. The shell is generally pinkish-red in color, with striped variegation to darker shades appearing in many individuals. The adductor muscle itself is large, often in diameter. Like all scallops, P. magellanicus has photoreceptive eyes along the edge of the pinkish mantle. Range and habitat Placopecten magellanicus is found on the continental shelf of the northwest Atlantic from the north shore of the Gulf of St. Lawrence south to Cape Hatteras, North Carolina. Sea scallops typically occur at depths ranging from 18–110 m, but may also occur in waters as shallow as 2 m in estuaries and embayments along the Maine coast and in Canada. In southern areas, scallops are primarily found at depths between 45 and 75 m, and are less common in shallower water (25–45 m) due to high temperature. Although sea scallops are not common at depths greater than about 110 m, some populations have been found as deep as 384 m, and deep-water populations at 170–180 m have been reported in the Gulf of Maine. Sea scallops often occur in aggregations called beds. Beds may be sporadic (perhaps lasting for a few years) or essentially permanent (e.g., commercial beds supporting the Georges Bank fishery). The highest concentration of many permanent beds appears to correspond to areas of suitable temperatures, food availability, substrate, and where physical oceanographic features such as fronts and gyres may keep larval stages in the vicinity of the spawning population. Adult sea scallops are generally found on firm sand, gravel, shells, and rock. Other invertebrates associated with scallop beds include sponges, hydroids, anemones, bryozoans, polychaetes, mussels, moon snails, whelks, amphipods, crabs, lobsters, sea stars, sea cucumbers, and tunicates. Fishery According to NOAA, the Atlantic sea scallop fishery is healthy, and is harvested at sustainable levels. The federal fishery is managed by NOAA Fisheries and the New England Fishery Management Council. The U.S.