Densley Sampled 

 Moderately Sampled 

 Stations 



°o°°°°Oo /# 



Figure 1. — Sampling areas and stations for Fisheries Research Board of Canada cruises. 



At each station, oceanographic data (tempera- 

 tures, salinities, and oxygen content) were col- 

 lected, and plankton tows were made. Three types 

 of surface nets ("Lobster. "" "Neuston," and "Her- 

 ring"" nets) were used on the 1965 cruise (Tibbo and 

 Lauzier. 1969). On more recent cruises most of the 

 surface sampling was carried out with the "Neus- 

 ton"" net, which consists of an oblate meter ring 

 with a 30 X 100 cm opening (Bartlett and Haedrich. 

 1968). Several deep tows were made with other 

 nets. "Neuston"" nets were towed at 4-6 knots, 

 while other nets were towed at various speeds from 

 2 to 5 knots. 



RESULTS 



During the eight Fisheries Research Board 

 (FRB) cruises a total of 119 swordfish larvae was 

 captured. 



» These larvae, ranging in size from 6.5 mm to 

 110.6 mm, were found scattered over a large area 

 (Table 2, Fig. 2). but there was no obvious pattern 

 in size distribution with respect to time or location. 

 Two small larvae were found east of Cape Hatteras 

 in March. Many larvae were caught in the Gulf 

 Stream from the Florida Straits to Cape Hatteras 



during the months of January through March. 

 Specimens were taken in the northeastern Gulf of 

 Mexico (early March) and south of Cuba (late Feb- 

 ruary). The regions west of the Lesser Antilles and 

 southwest of Barbados were sampled in January 

 and in March, yet larvae were found only in late 

 March. Specimens were obtained in the Virgin 

 Island-Leeward Islands area from January to 

 March. 



Sampling in the following areas produced no lar- 

 vae: Bermuda (January, May); northeast of Cape 

 Hatteras (January, February, April. May); south- 

 ern Caribbean (late February, early March); 

 southwestern and central Sargasso Sea (January, 

 February). 



Although surface temperatures ranged from 

 6.6°C to 26.9°C, larvae were found only at stations 

 where temperatures were above 22.4°C. Similarly, 

 within a total salinity range of 33.40''/oo to 37.88%o 

 larvae were caught only where the salinity was 

 35.40''/oo or more. 



All but three of the larvae were taken in surface 

 tows. The exceptions were caught in oblique tows 

 and hence may have been captured as the net 

 neared the surface (Tibbo and Lauzier, 1969). 



253 



