192 



distal margin, slightly wider at tip of upper lobe. Anal fin with several large brown 

 or black spots near the base, and with a dark black marginal band. 



Distribution 



Tetranematichthys quadrifilis is widely distributed throughout both the 

 Orinoco and Amazon basins (Fig. 37), The widely disjunct records and the 

 relatively small amount of material deposited in museums probably reflects 

 difficulty in collecting this species, rather than natural rarity. 



.''v_ 



Etymolog y 



The generic name from the Greek tetra, four, and nematos, thread; the 

 specific epithet from the Latin quadras, fourfold, andfilum, thread. Both names of 

 the binomen emphasize the presence of four barbels in adults of this species. 



Ecology 



Nothing published. In terms of its preferred habitat, Tetranematichthys may 

 be more similar to most auchenipterids than to other ageneiosids; cursory 

 observations by H. A. Britski (personal communication) are that T. quadrifilis is 

 found in relatively slow-moving backwater areas or small streams, such as in gallery 

 forests, in contrast to species oiAgeneiosus, all of which are most commonly 

 collected in the main chaimels, lakes, or oxbows of large rivers. : " 



'•i. 



\ :' 



1 



^ ^^V>^ 



«L* 



»■ V i' M 



■ O! K^^- 



