36. 



The fauna in the axis of Lydonia Canyon is also heavily 

 dominated by shrimp (1) . This reflects the greater amount 

 of hard substrate exposed within the axis and along the lower 

 parts of the walls. Two areas were identified in Lydonia 

 Canyon that deviated from these general trends. An area of 

 consolidated clay is located between 400 to 500 meters on the 

 west flank. The fauna here is dominated by a species of 

 Munidat which may be Munida valida since specimens have been 

 trawled from depths exceeding 500 meters (Haedrich and Rowe, 

 unpublished results) . Additionally, in the shallow axis high 

 concentrations of Pennatula aaulata are found between 400 and 

 600 meters. 



Species similarity analysis of the fauna of Oceanographer 

 Canyon does not show as distinct a pattern as was found in the 

 other two canyons (Fig. 18) . This difference is probably 

 the result of the lack of shallow water coverage, so that the 

 variable shallow-water assemblage was not seen. However, 

 the results do show a more complicated pattern for the deeper 

 fauna. The faunal variability within this depth range is 

 probably caused by the heterogeneous substrates found within 

 this canyon. In areas of silty sediment the fauna is 

 dominated by the red crab Geryon quinquedens j the eel 

 Synaphobranahus kaupi a:nd rattails,with the ophiurid 

 Ophiomusium lymani dominating the fauna in the deeper axis. 

 In areas characterized by variable substrate, including numerous 



