MUSICK: SEASONAL DISTRIBUTION OF SIBLING HAKES 



intensity does not give a true indication of its 

 presence or absence. During the fall, immature 

 U. tenuis occurred over the entire temperature 

 range, 4° to IS^'C. In the winter, they were taken 

 from 3° to 10°C. In the Gulf of Maine in the sum- 

 mer, immature U. tenuis occurred from 4° to 9°C 

 and the highest mean catch was at 8°C. The fish 

 were absent at 3°C and from 10° to 14°C; how- 

 ever, these temperature intervals were not ade- 

 quately sampled. In the fall, immature U. tenuis 

 occurred from 3° to 11°C and the highest mean 

 abundance was at 9°C. The fish were absent 

 from 12'' to 15°C but the sampling intensity at 

 these temperatures was inadequate. In the winter, 

 only a few fish were taken at 2°C and 3°C and 

 mean catches increased from 4° to 7°C. Im- 

 mature U. tenuis were taken over an annual 

 range of 2° to 15°C but were most abundant be- 

 tween 4° and 10°C (Figure 20). 



During the summer (Figure 21), mature U. 

 tenuis were rare or absent off southern New Eng- 

 land except in two strata deeper than 100 fm. 

 They were moderately abundant in the Gulf of 

 Maine and heavily concentrated in Stratum 39 

 along the northern coast of Maine. In the fall 

 (Figure 22), off southern New England, mature 

 U. tenuis were moderately abundant in all strata 

 deeper than 100 fm, in two strata from 60 to 99 fm 

 deep, and in only one stratum from 30 to 59 fm 

 deep. They were rare or absent in all other south- 

 ern New England strata. Mature U. tenuis were 

 mo^lerately abundant in the Gulf of Maine. The 

 highest values of abundance are in Strata 27 and 

 28, between 60 and 100 fm. 



SUMMER 

 n: 35r 



GULF OF MAINE 



FALL 



/\ 



3 4 5 6 7 8 9 10 II l2 i3 



SOUTHERN NEW ENGLAND 



WINTER 

 n:634 



^^4£r 



a 



f^ 



5 6 7 a 9 10 II 12 II 14 15 16 



kq.^764i& 



1 



4 5 6 7 8 9 to II t2 13 14 15 2 3 4 5 6 7 8 9 10 II 



TEMPERATURE l°C) 



Figure 20. — Seasonal catch per tow of immature Urophycis 

 tenuis off southern New England and the Gulf of Maine. 

 Abundance data are stratified by temperature intervals of one 

 degree (C). The total number of individuals captured during 

 each season = n. The number of stations occupied at each 

 temperature is indicated above each respective histogram bar. 



During the winter off southern New England 

 (Figure 23), mature U. tenuis were rare or absent 

 in all strata shoaler than 100 fm except Stratum 

 7, which was 60 to 99 fm deep. Mature U. tenuis 

 were moderately abundant there and in all strata 

 deeper than 100 fm. In the Gulf of Maine, 

 mature U. tenuis were absent from all strata 



WINTER 

 9-50 cm Totol length 



Ho 



n 5-0.24 

 n 0.25-0.99 

  100-2.49 



Figure 19. — Distribution and abundance of immature Uro- 

 phycis tenuis during the winter. Abundance in each sampling 

 stratum is indicated on a log scale. 



SUMMER 

 >5I cm Totol length 



11 



□ <-0.24 



□ 0.25-0.99 

  >250 



Figure 21. — Distribution and abundance of mature Urophycis 

 tenuis during the summer. Abundance in each sampling stratum 

 is indicated on a log scale. 



491 



