Figure 3. — Relative abundance of the calico 

 scallop, Cape Kennedy grounds, 1960-1966. 

 One fathom equals 1.8 m. (Modified from 

 Drummond, 1969.) 



than size," and suggested that spawning can be- 

 gin at a young age. 



Spawning in the calico scallop, similar to that 

 in certain other bivalves, is perhaps controlled 

 primarily by water temperatures and may be 

 initiated by rising temperatures (Roe, Cum- 

 mins, and Bullis, 1971) . The gonads of scallops 

 caught on the Cape Kennedy grounds in October 

 1969 and maintained in the laboratory at about 

 25 °C changed color from light pink to orange- 

 red within 2 weeks. These scallops were then 

 induced to spawn (Fig. 4) by rapidly raising 



the ambient water temperature to 30°C (Miller 

 and Drummond).'" Conversely, low tempera- 

 tures may terminate spawning (Roe, Cummins, 

 and Bullis, 1971). 



Several methods have been used to determine 

 the seasonal pattern of spawning of the calico 



'" Miller, G. C, and B. R. Drummond. 1969. Report 

 on gonadal color change and spawning of calico scallops 

 at TABL, October 23-November 13, 1969. Unpublished 

 report, 5 p., filed at the National Marine Fisheries Ser- 

 vice, Southeast Fisheries Center, Miami Laboratory, 

 Miami, Fla. 33149. 



