BATHYPELAGIC SQUID BATHYTEUTHIS 



135 



Figures 39 to 42 present the frequencies of occurrences of B. dbyssi- 

 eola at in situ values of oceano<>rapliic parameters. Table VIII gives 

 the numbers and percents of captures and individuals taken at simul- 

 taneous ooeanographic values. 



Figure 39 is a histogram of the frequency of occurrence of captures 

 and individuals at 0.5° C increments. A gi*adually increasing number 

 of tows caught a greatly increasing number of specimens as tlie temper- 

 atures increase from 0° to 2.5° C. A sudden drop-off in numbers occurs 

 in waters warmer than 2.5°. Of the successful tows 28% captured 37% 

 of the total number of individuals at temperatures l^etween 2.0° and 

 2.49° C (Table VIII). Another 28^, of the tows caught 32% of the 

 population between 1,50° and 1.99° C. Therefore, in the 1° range be- 

 tween 1.5° and 2.49° C, 56% of the captures accounted for 69% of the 

 individuals. Between 1.0° and 2.49° C, 85%- of the population was 

 captured by 75% of the tows. 



The histogram for salinity shows a very low number of catches and 

 individuals below 34.60%o (fig. 40). The'34.60-34.69%o and the 34.70- 

 34.79%o columns have been subdivided for a more detailed breakdown 

 of salinity frequencies. The first of these columns represents 34% of 

 the population with 28%. of the tows and the second 52% of the popu- 

 lation in 55% of the tows. Of the captured population 82% of the 

 individuals came from salinities between 34.64 and 34.75%o and 52% 

 from 34.70 and 34.75%o. The sudden drop-oil above 34,75%o is not due 

 to exclusion of B. ahys>iicola from higher salinity waters; the salinity 

 at the depths where this species occurs in the Antarctic very seldom, if 



Figure 39. — Frequency of captures and individuals of Bathyteuthis abyssicola at tempera- 

 ture increments in the Antarctic Ocean. Hatched area is number of captures (n=136); 

 clear area is number of individuals (n = 591). 



