The "percent similarity" index was used as a mathematical indication of 

 faunal similarity. The resulting cluster structure was a function of both 

 depth and location within the canyon. Clusters grouped at relatively low 

 percentages (15), an indication that many of the taxa were patchily 

 distributed. 



Geographical mapping of the cluster results shows 5 broad faunal zones 

 (using the word "zone" loosely since clusters were usually a result of high 

 abundances of few species and clusters only grouped at 15 percent similarity) 

 on the walls and flanks of the canyon. The faunal distributions within the 

 canyon axis at depths of less than 1,500 m were extremely patchy and complex, 

 reflecting the substrate heterogeneity and active physical regime. 



Cluster 1 consists of areas that are centered on the 200-m isobath around 

 the canyon rim. Species common to all areas in this cluster are crabs {Cancer 

 sp.), black-bellied rosefish, the anemone, Actinauge longicorm's, and the 

 starfish, Sclerasterias tanneri . 



Areas in cluster 2 range from 300 to 475 m but do not extend into the 

 canyon past the upper flanks. Common species are Bolocera tudiae, Hyal inoecia 

 artifex, Actinauge verilU, and long-finned hake. 



Areas in cluster 3 are between 500 and 1,000 m and have a mud to cobble 

 substrate, with Synaphobranchus kaupi , Geryon quinquedens, Glyptocephalus 

 cynoglossus, and Asbestopluma sp. 



Areas in clusters 4 and 5 are the deepest, with Distichoptilum gracile 

 and a cerianthid anemone in both and Ophiomusium lyman] in 5. 



In contrast, the clusters consisting of axis areas (clusters 7, 8, 9) are 

 typified by a variety of corals and sponges, in addition to the background 

 fauna of clusters 1-5. 



- 64 



