BATHYPELAGIC SQUID BATHYTEUTHIS 143 



from Circumpolar-Transitional water at lower salinity (around 

 34.65%o) and slightly higher temperature (2°-2.35°C). 



Although there are some areas in the Antarctic waters studied to 

 date where B. ahyssicola is more abundant than in other areas, it is 

 reasonable to assert that this species is circumpolar in distribution; 

 when the remaining portion of the Antarctic Ocean is explored (the 

 eastern half), probably no signficant changes will be required in the 

 distributional pattern as it is now understood. 



The easternmost record of B. ahyssicola in Antarctic waters is 

 Hoyle's type specimen from 46°16'S 48°27'E between Prince Edward 

 and the Crozet Islands. No further captures are recorded across the 

 Indian or southwestern Pacific-Antarctic Waters until the area of 

 operation of the Eltanin southeast of New Zealand. The southernmost 

 location for B. ahyssicola is recorded by Hoyle (1912) at 71°22'S 

 18°15'W off Coates Land. Eltanin specimens were taken a little beyond 

 66°S in the Bellingshausen Sea during Cruise 13. Future cruises of 

 Eltanin into higher latitudes should disclose the southern limit of dis- 

 tribution of Bathyteuthis ahyssicol'tt.. The limit will correspond, in 

 part, to water that shoals above 1500-2000 m. Presumably this species 

 inhabits the bathypelagic zone of the entire circumpolar ocean. 



Eastern Pacific Ocean 



The T-S capture diagram (fig. 44) for Bathyteuthis in the eastern 

 Pacific Ocean along South and Central America reveals that the genus 

 occurs in two distinct wat^r masses. Captures of B. ahyssicola that were 

 made in the Peru Current between about 33° and 51 °S fall along the 

 T-S values of Antarctic Intermediate Water; the jjoints at the gi'eater 

 depths (2000-3000 m) overlap with Pacific Upper Deep Water. The 

 locations of captures of B. hacidifera and B. ahyssicola in the eastern 

 tropical Pacific are plotted in figure 45 where they lie in the Pacific 

 Equatorial Water Mass. This relatively warm, saline w^ater mass at- 

 tains its characteristics by in situ advective mixing. In the area of the 

 captures otF Central America the thermocline is shallow and a pod of 

 nutrient-rich deep water ascends to the euphotic zone and is responsible 

 for the region's high productivity. The T-S capture plots for both 

 species are clustered in the 700-1750 m section of the Pacific Equatorial 

 Water Mass envelo^je where the temperature ranges from 3°-6° C and 

 the salinity ranges from 34.55-34.65%o. Records from the literature 

 include Hoyle's (1904) in the Bay of Panama and Robson's (1948) 

 around Cocos and Galapagos Islands. 



The Dana and Eltanin specimens and Robson's (1948) records are 

 plotted on the vertical sections of hydrographic parameters (figs. 46- 

 49). One of Robson's specimens, a larva, was taken at 550 m where 



