BATHYPELAGIC SQUID BATHYTEUTHIS 127 



The thick layer of the salinity maximum, with salinities of 34.T2%o 

 to 34.73%o, occupies the depths between 750 m and 1800 m in the south 

 and 1600 m to 2800 m at 55 °S. A tongue of 34.7l:%o water protrudes 

 from the Pacijfic Deep Water to the north and terminates at 55°30'S in 

 2000-2500 m. The lines of equal density slope to deeper water toward 

 lower latitudes; the sigma-t= 27.75 line nearly parallels the 34.70%o 

 isohaline. Minimum oxygen concentrations of 4.43 ml/L to 4,33 ml/L 

 occur between 600 and 450 m between 65°30' and 62°S. Then the 

 oxygen minimum layer descends gradually to 1500 m at 55°S with a 

 value of 4.05 ml/L. Isopleths of oxygen concentration also descend 

 from south to north. 



Twelve tows that were successful in catching B. abyssicola between 

 120° and 145 °W are plotted on the sections. The captures were made 

 during Cruises 13, 14, and 15. The plots on the temperature section for 

 the most part correspond well with the simultaneous temperatures. 

 Two deep tows (2400 m) that captured nine specimens lie at or just 

 below the 1.5° isotherm. The three tows in 1700-1^0 m at 57°-58°S 

 occur beneath the 2° isotherm. All but one of the remaining tows lie 

 between the 2° and 2.5° C isotherms. The temperature plots for the two 

 tows near 35 °S do not correspond with the simultaneous temperatures. 

 The tow at 705 m had a simultaneous temperature of 2.16° C and 

 the capture at 1080 m had a simultaneous temperature of 2.96° C. The 

 five tows between 625 and 1080 m captured thirteen Specimens; twelve 

 of them were larvae and juveniles. The two tows at 1250 m, just above 

 the 2° isotherm between 57°30'' and 59°S, captured 40 specimens, and 

 the five tows below the 2° isothemi caught 28 specimens. Seven im- 

 successf ul tows were made in the region under discussion : four between 

 500-600 m, two between 1000-1100 m, and one at 2300 m. 



On the salinity section nine captures occur below the 34.60%o 

 isohaline ; four of these are in the layer of maximum salinity. The shal- 

 low tow around 55°S is plotted in relatively low salinity just under 

 34.40%o, but its simultaneous salinity is 34.68%o. Six shallow tows are 

 in densities l)elow sigina-t = 27.75, and tlie remaining six tows are above 

 that value, five of them betw:een 27.80-27.85. All specimens were taken 

 at oxygen concentrations between 4.05 ml/L and 4.75 ml/L and most 

 were between 4.20 ml/L and 4.50 ml/L. All but one were in or below the 

 oxygen minimum layer. 



In summary, only one tow was successful in water warmer than 

 2.5°C, and most captures were made within 0.5° C of the 2° isotherm. 

 The shallowest tows contain primarily larval and juvenile specimens. 

 Only two tows were in less than 34.60%o salinity, and six tows were 

 above 34.70%o. A range of densities is occupied by the plots, but most 

 are above sigma-t = 27.60. Most specimens were located in or l)elow the 



