Distribution of Larval Swordfish 

 in the Northwest Atlantic Ocean 



GRETCHEN E. MARKLE 1 



ABSTRACT 



Surface plankton collections, mostly with neuston nets towed at 4-5 knots, during eight 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 study 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 1. — Fisheries Research Board of Canada swordfish cruises. 1965-1972. 











No. of 









No. of 



larvae 



Cruises 



Dates 



Locations 



stations 



captured 



BIO-3 



3-24 Feb. 1965 



Sargasso Sea, 

 Virgin Islands 

 Gulf Stream 



36 



47 



ATC-11 



25 Jan. -11 Feb. 1966 



Gulf Stream 



31 



9 



EEP-3 



4-18 Apr. 1967 



NE of Cape Hatteras 



14 



2 



Hudson-68 



24 Mar-2 Apr. 1968 



SE of Barbados 



11 



8 



CODC-69-003 



1 Jan-5 Feb. 1969 



Sargasso Sea, 

 Lesser Antilles 



51 



10 



CODC-69-023 



28 Apr.-19 May 1969 



N of Bermuda 



19 



— 



CODC-70-004 



14 Feb- 13 Mar 1970 



Caribbean, 

 Gulf Stream 

 system 



50 



25 



CODC-72-004 



25 Feb. -23 Mar. 1972 



Lesser Antilles 

 Southern Caribbean, 

 Gulf Stream 



68 



18 







Total 



280 



119 



252 



