ATLANTIC 

 OCEAN 



Figure 2— Months of peak catch of the dolphin, Coryphaena hippurus, and proposed migration circuits for northern and southern dolphin 

 stocks in the western central Atlantic. Letter symbols (eg., A-M) indicate months of peak catch. M^t indicate proposed migration. 

 i S indicate proposed migration where catch data were not available • indicate locations from which samples for electrophoresis 

 were collected. 



continued growth of the cohort as it leaves Bermuda 

 and returns southwards into the northern Caribbean 

 for the winter. Note that since dolphin are serial 

 spawners and since fecundity is proportional to size 

 (Beardsley 1967; Oxenford and Hunte in press), most 

 spawning by a cohort will occur when the dolphin 

 comprising it are large For the northern dolphin, 

 this would be when the stock is near Puerto Rico, 

 i.e, at the southeastern or up-current limit of their 

 range Peak spawning near Puerto Rico is reported 

 to occur in early spring (Erdman 1976) and presum- 

 ably produces the small young-of-the-year fish caught 

 near Florida during the summer. 



The size structure of dolphin caught at Barbados 

 (Fig. 4) is consistent with the proposed migration 

 for the southern stock. In February, the main cohort 

 is composed of fish about 5V2 mo old with a mean 

 standard length of 812.24 mm. Growth within this 

 cohort occurs throughout the fishing season to June, 

 when the average fish size is 1,007.83 mm SL (Oxen- 

 ford and Hunte 1983). After this, abundance drops 

 sharply (Fig. 1) as the cohort leaves Barbados 



10 -, 



en 



u 



s 





6 - 



2 - 



BARBADOS 



FLORIDA NORTH BERMUDA BAHAMAS 

 CAROLINA 



Figure 3— Mean weights of individuals of the dolphin, Coryphaena 

 hippurus, landed during peak fishing seasons at five locations in 

 the western central Atlantic. 



migrating northwards. During early summer (June/ 

 July) and early autumn (October), the presence of 



454 



