BATHYPELAGIC SQUID BATHYTEUTHIS 59 



B. herryi is most readily distinguished from ahysmcola by the 

 extreme abundance of suckers on the arms and by long, wide gills. 

 (The significance of gill size is discussed in a later section.) The 

 arms of the holotype of herryi are 5-7 mm longer than the arms of 

 obyssicola of the same mantle length (49 mm), and they are more 

 attenuate. This trend holds in all specimens available. When material 

 with tentacles in tact becomes available, differences in the clubs may 

 be found. Although it is difficult to demonstrate quantitatively with 

 the limited number of specimens on lumd, the mantle of herryi appears 

 to be slightly more plump that that of ahyssieola. 



Comparison of Bathyteuthis abyssicola and 

 Bathyteuthis bacidifera 



Morphological Comparison 



The most striking and readily observable difference between Bathy- 

 teuthis hacidifera and B. ahyssicola is the possession of long, free, 

 finger-like trabeculae on the arms of B. hacidifera. B. abyssicola lacks 

 this feature entirely, although its protective membrane differs from 

 most other oegopsids by being thick, fleshy (semigelatinous), and 

 unsupported by strong trabeculae. The protective membrane of abyss- 

 icola exhibits considerable individual variation; the border may vary 

 from straight and smooth to gently undulating or scalloped, but a 

 comblike row of trabeculae does not occur. The free trabecular rods 

 of bacidifera are well developed on the smallest specimens observed 

 (6 mm ML), so there is no danger of confusing even the larvae of 

 the two species. The erection of a separate species might be warranted 

 on the basis of this feature alone, but other less spectacular specific 

 characters do exist. 



The clubs of bacidifera are longer and bear more suckers than do 

 those of abyssicola of the same size. For example, the clubs of the 

 liolotype of hacidifera (37 mm ML) and of an abyssicola of 57 mm ML 

 are nearly equal in length, but hacidifera has about 615 suckers on the 

 club wliile abyssicola has around 525 suckers. An analysis of club 

 lengths is presented in the following section. 



The gills of bacidifera are measurably larger than those of abyssi- 

 cola and they tend to have a greater number of filaments. Geographic 

 variation exists in the gill size of abyssicola from different areas but 

 little overlap occurs with hacidifera. A detailed analysis of gill size 

 appears in the section on geographical variation. 



Within species, suCker dentition varies slightly with the size of the 

 specimen and with the size of the suckers on an individual specimen. 



321-534 O— 69 5 



