McEACHRAN and MUSICK: DISTRIBUTION AND RELATIVE ABUNDANCE OF SKATES 



SOUTHERN MID-ATLANTIC 

 BIGHT 



UJ 



o 



z 2 -t 

 < 



Q 



Z 



CD 



< 



^ I H 



X 



LlJ 

 Q 



_3^ 

 10 



2 5 6 



n 



13 11 



3 2 



NORTHERN MID-ATLANTIC 

 BIGHT 



I 



GEORGES 



BANK 



Ts 





10 



15 



20 C 



15 



20 C 



10 



r 



15 C 



2-1 



o 



z 

 < 

 o 



z 



< 



X 



UJ 



a 



GULF OF MAINE 



12 



r 



4 10 191 |6 



NOVA SCOTIAN SHELF 



4 3 I 



15 20 C 



TEMPERATURE 



"T 

 5 



8 



r 



10 



15 



20 C 



Figure 10.— Index of abundance (geometric mean) of Raja erinacea captured in each subarea during autumn 1969 within tempera- 

 ture intervals of TC. See Figure 3 for explanation of fractions and whole numbers. 



Raja senta 



Raja senta was taken in the Gulf of St. 

 Lawrence, along the northeastern coast of Nova 

 Scotia and, contrary to the reports of Bigelow 

 and Schroeder (1953) and Leim and Scott (1966), 

 it was fairly abundant on the offshore banks of 

 Banquereau, Sable Island, and Western. It was 

 found throughout the Gulf of Maine, off southern 

 Nova Scotia, and on Georges Bank (Figure 15). 

 No seasonal trends in abundance were noted. 

 Depth of capture ranged from 31 to 413 m but 

 it was most abundant below 110 m. Bigelow and 

 Schroeder (1953) stated that R. senta occurred 

 between 46 and 874 m and was most abundant 



between 91 and 457 m. This species was found 

 at temperatures from 0.5° to 4.8°C in the Gulf 

 of St. Lawrence, -1.3° to 11.8°C off northeastern 

 Nova Scotia, and 2° to 10°C from southern Nova 

 Scotia to Georges Bank. In the northern part 

 of its range, it was occasionally caught at tem- 

 peratures less than 2°C, which Bigelow and 

 Schroeder (1953) stated was the minimum 

 temperature for the species. 



Raja senta is a boreal species whose center of 

 abundance occurs in the Gulf of Maine, where it 

 is found over the greater part of the range of 

 temperatures (Figures 16-18). It is found only at 

 the lower part of the temperature range on 

 Georges Bank. 



123 



