Evidence of a semiannual reproductive cycle for the sea scallop, Placopecten magellanicus (Gmelin, 1791), in the Mid-Atlantic region
The reproductive cycle of the sea scallop, Placopecten magellanicus in the mid-Atlantic region was studied over a 15 month period. One to 15 samples a month were collected from commercial vessels fishing from Long Island to Cape Hatteras in water depths of 37-68 m. Gonad weights were determined for 4 shell size intervals as an indicator of the reproductive cycle. A sharp decline in mean gonad weights between April-May 1987 and a subsequent increase and decrease in weights between September-November 1987 indicated reproductive processes were occurring on a semiannual cycle. A major spring spawning season was reconfirmed in 1988 by a rapid increase in mean gonad weights between December 1987-January 1988, followed by variable declines in the weights through June. The occurrence of spawning activity for 2 consecutive spring seasons in addition to a fall spawning season suggests that a semiannual reproductive cycle may be a characteristic feature of P. magellanicus in the mid-Atlantic region. The ramifications of spring spawning to the mid-Atlantic sea scallop fishery and management policies are addressed.