Distribution of Larval Swordfish 

 in the Northwest Atlantic Ocean 



GRETCHEN E. MARKLE^ 



ABSTRACT 



Surface plankton collections, mostly with neuston nets towed at 4-5 knots, during eiglit cruises 

 (1965-1972) yielded 119 swordfish larvae 6-110 mm total length. Captures were grouped in discrete 

 geographical areas: Virgin Islands, Guiana current, Northwest Caribbean, Windward Passage, and 

 Florida current. All collections were made in January-April, but comparison with other published data 

 suggests that this may not be the peak spawning period. Descriptions of swordfish larvae are appended. 



In 1965. a program was initiated to sttjdy the dis- 

 tribution and early life history of large pelagic fishes 

 in the Northwest Atlantic Ocean. Forty-seven 

 swordfish larvae were captured during the first 

 cruise, which covered the Sargasso Sea, the Virgin 

 Islands, and the Gulf Stream off Florida. Since re- 

 latively little is known of the growth and behavior of 

 young swordfish, subsequent cruises were designed 

 to carry out a more systematic search for specimens 

 and to study the environmental conditions under 

 which they occur. 



'Fisheries Research Board of Canada. Biological Station. St. 

 Andrews. New Brunswick. Canada. 



The 1965 data have already been reported (Tibbo 

 and Lauzier, 1969). In this report, all of the data are 

 considered. 



MATERIALS AND METHODS 



Eight cruises were made during the period 

 1965-1972 (Table 1). Of these, five were to the 

 Caribbean and adjacent seas, and three were to the 

 Gulf Stream north of lat. 25°N. Most of them were 

 carried out during the months of January, Feb- 

 ruary, and March. Two of the Gulf Stream cruises 

 were in April and May. In all, 280 stations were 

 occupied (Fig. 1). ^ 



Table I. — Kisheries Research Board of Canada swordfish cruises. 196.'^-I972. 



252 



