BATHYPELAGIC SQUID BATHYTEUTHIS 



163 



adaptation to fluctuating conditions and has dispersed to the produc- 

 tive regions of higher hititudes and has differentiated into distinct 

 geographic popuhitions. The more restricted B. hacidifera.^ on the 

 other hand, apparently does not share this degree of adaptability 

 and is limited to equatorial waters of the eastern Pacific Ocean (and 

 possibly the Indian Ocean). 



Summary of Distribution With Physicochemical and 

 Biological Factors 



B. ahyssicoJa inhabits several different water masses and is capable 

 of crossing water-mass boundaries particularly to follow zones of 

 high productivity. Within particular water masses, however (e.g., 

 Antarctic Circumpolar, Pacific Equatorial, and Atlantic Central), 

 B. ahymlcola exhibits geographical populations. B. hackUfera on the 



Figure 61.^Summary of T-S-densit>- relationship of Bathyteuthis captures in the Ant- 

 arctic, Atlantic, Pacific, and Indian Oceans. The boxes outline areas of occurrence. Ab- 

 breviations as follows: 



I, Indian Ocean a, Antarctic Intermediate (Pacific) 



N, North Atlantic Ocean c, Circumpolar Water Mass (majority of 



s, South Atlantic Ocean captures) 



p, Pacific Equatorial Water c, Circumpolar Water Mass (few captures) 



