61. 



Geryon Quinquedens and two types of demersal fish, rattails 

 and the eel Synaphobranahus kaupi. Gradation in this diference 

 is seen by a closer examination of the mid-depth fauna in the 

 three canyons studied. Of these canyons Baltimore Canyon most 

 closely resembles slope habitats, in that this canyon evidences 

 the least amount of substrate variability. This is reflected 

 in the fauna of the mid-depth range which is dominated by the 

 same three species that are also abundant on the slope. In 

 the northern canyons sessile filter- feeders frequently are 

 important constituents of the fauna at these depths, and thus 

 G, quinquedens, Synaphobranchus kaupi and ra.ttails are not 

 as dominant. 



Community analysis identified a rather variable shallow- 

 water assemblage (100-400 m) and a less variable deeper one. 

 This is similar to the trends seen on the slope and was the 

 most pronounced in Baltimore Canyon. The fauna of the mid- 

 depth region (400-1100 m) of the northern canyons tended to 

 be somewhat more variable. Principal components analysis 

 did not identify any cohesive assemblages of species. The 

 results indicate that the majority of the dominant species 

 found in the canyons are independently distributed. This 

 means that these species are responding to different environ- 

 mental parameters. 



