FAHAY: OCCURRENCE OF SILVER HAKE EGGS AND LARVAE 



Table 4. — Numbers of silver hake larvae collected during six 

 cruises in 1966. 



than 18.0 mm NL until the August cruise (Figure 

 9). Since the spawning season probably began in 

 early June, and since 18.0 mm approximates the 

 size at which silver hake postlarvae begin to live 

 near the bottom, the length of pelagic life is 

 apparently about 2 mo. 



Within our 1966 sampling area, larvae were 

 most densely concentrated between Nantucket 

 Shoals and Hudson Canyon. Progressing south- 

 ward, we found larvae increasingly restricted to 

 the offshore part of the shelf. Distribution varied 

 according to the size of larvae. Generally, we 

 found smaller larvae inshore and near the surface. 



and larger larvae offshore and deeper. Smaller 

 larvae were also more numerous in the north- 

 eastern part of the survey area than the south- 

 western. Tables 5 through 7 illustrate this trend 

 for the August, September, and October cruises. 

 These differences in distribution by size are partly 

 a result of a southwesterly drift during grov^h, 

 partly a preference by larger larvae for deeper 

 water. 



Silver hake larvae in 1966 were distributed 

 in areas where surface temperatures ranged from 

 8.6° to 25.8°C. Since silver hake larvae are not 

 necessarily surface-dwelling animals, the mean 

 observed temperatures within the depths sampled 

 by the two Gulf V nets may be more significant. 

 Table 8 shows the number of tows containing 

 larvae (arranged by volume of catch) relative to 

 these temperatures. The total number of tows, 

 regardless of the presence of silver hake, is in- 



130 35' 



NOTOCHORD LENGTH (1 - mm GROUPS) .= less than 1 per cent 



Figure 9. — Length-frequency distributions of silver hake larvae during five cruises, 1966. 



823 



