BATHYPELAGIC SQUID BATHYTEUTHIS 



183 



Figure 69. — Influence on curve of vertical distribution of 16 tows that caught 9 or more 

 specimens, a, curve for total sample population; b, curve exclusive of the 16 exceptional 

 tows. Antarctic. 



3. Seasonal Abundance 



Although seasonal data are incomplete, there is some indication 

 of seasonal fluctuation in the abundance of B. ahyssicola. Of the 

 16 tows that captured more than 9 specimens (totaling 210 speci- 

 mens), 12 were taken durino- October, November, and December 

 (5, 0, and 2 tows respectively), 3 were taken in August and Septem- 

 ber, and 1 was taken in July (well north of the convergence) (Table 

 XV). No such large captures were taken between April and July. 

 Furthermore, a breakdown of successful to unsuccessful tows by 

 months indicates that more tows were successful during the austral 

 late spring and early summer months. During October, November, and 

 December there were 74 successful tows and 40 unsuccessful tows, a 

 success rate of 659^ or nearly 2 to 1. During August and September 

 there were 34 successful tows and 22 unsuccessful tows, for 60*^ suc- 

 cess, or 1.5 to 1. In April through July there were 20 successful and 

 27 unsuccessful tows for a success rate of 42% or 0.74 to 1. These winter 

 values, liowever, may be more a factor of locality than of season, be- 

 cause one cruise is primarily responsible for the reverse of the suc- 

 cessful to unsuccessful ratio. Cniise 8 took place during April and May 



