BATHYPELAGIC SQUID BATHYTEUTHIS 85 



values nearer the surface and in greater depths may exceed these 

 vahies. The few specimens of ahy-ss/'coJa captured in the eastern Pacific 

 were taken in the same stations as the deej:)er specimens of haeidifera 

 where oxy<2:en values ranged from 1.12 ml/L to 1.47 ml/L. Oxygen 

 concentrations in the eastern tropical Pacific do not exceed 2.0 ml/L 

 until depths greater tlian 2000 m (Sverdrup et al., 1942; Wooster and 

 Cromwell, 1958). The Atlantic specimens of ahyssicoJa came from a 

 broad range of oxygen concentrations with extremes of 2 ml/L and 

 6 ml/L, but generally the values were 3-5 ml/L. 



The correlation between oxygen concentration and gill size in Bathy- 

 teufhis, as in ScopeJogadui^, prompts speculation that larger gills pro- 

 vide more efficient means of obtaining oxygen. The possibility may be 

 further strengthened by the fact that when the two species of Bathy- 

 teuthis occur in the same area of extremely low oxygen concentrations 

 they both possess longer, wider gills. 



Relationship of Ctenopteryx to Bathyteuthis 



Shortly after its description by Appelof in 1890 Ctenopteryx was 

 united with Bathyteuthis in the Bathyteuthidae by Pfeffer (1900). 

 Most later authors accepted this designation (e.g., Chun, 1910 ; Pfeffer, 

 1912; Naef, 1923; Grimpe, 1922, 1925; Thiele, 1935) but generally 

 implied that the two genera were not closely related. To emphasize 

 the distinctiveness of the genera, Grimpe (1922) erected the subfam- 

 ilies Bathyteuthinae and Ctenopteryginae. Allen (1945) felt that even 

 subfamilial distinction was insufficient so she withdrew Ctenopteryx 

 from the Bathyteuthidae and elevated it to the family Ctenoptery- 

 gidae based solely on fin structure and body proportions. Allen's act 

 constitutes the latest revision of the higher taxa that encompass Cteno- 

 pteryx and Bathyteuthis. 



On the basis of the material at hand, it is necessary to reevaluate the 

 systematic positions and relationships of these two genera. 



A brief description of some taxonomic characters of Ctenopteryx 

 will help to determine the degree of similarity with Bathyteuthis. 

 Some of the characters compared may be only specific, but since the 

 species of Ctenopteryx are poorly understood, it is advisable to use 

 whatever characters are pertinent to this discussion. 



The funnel-mantle locking apparatus is tlie simple, straight ridge 

 and groove type. The funnel component is broad posteriorly and nar- 

 rows anteriorly ; the groove is deep and narrow. The funnel component 

 of Ctenopteryx is broader posteriorly, but in general the locking ap- 

 paratuses of the two genera exhibit no significant differences. 



