REPRODUCTION OF THE BAY SCALLOP, AEQUIPECTEN IRRADIANS LAMARCK. INFLUENCE OF TEMPERATURE ON MATURATION AND SPAWNING

¹ Oceanographic Institute, Florida State University, Tallahassee, Florida

1. Subspecies A. i. concentricus from Alligator Harbor, Florida, reaches maturity towards the end of July when the summer temperatures are maximum and commences spawning early in August as the temperatures begin to decrease.

2. Winter temperatures slow gonadal development of a Florida population of scallops. During winter, scallops were stimulated to maturity at elevated temperature of 23.0 ± 1.0° C. in 26 days.

3. Matured scallops maintained in the laboratory spawned in response to elevated temperature during different months of the year.

4. The subspecies A. i. irradians from Massachusetts and A. i. concentricus from Florida and North Carolina show differences in temperature requirements for maturation and spawning. The subspecies north of Cape Hatteras reproduce at lower temperatures as compared with the southern subspecies. The spawning of both the subspecies does not overlap.