37. 



outcrops, the fauna is composed mainly of shrimp and sponges 

 with several locations having high concentrations of the 

 coral 



Principal components analysis of the fauna of Oceanographer 

 Canyon resulted in 96% of the total variance being explained 

 by ten monospecific end-members. The plot of the end-members 

 of the fauna of Oceanographer Canyon shows that trends of 

 faunal replacement are not as apparent in this canyon, as 

 they were in Baltimore or Lydonia Canyons (Fig. 19) . This 

 finding again indicates that a possible reason for the lack 

 of pattern in Oceanographer Canyon is the heterogeneous 

 environment, in terms of substrate variability, afforded by 

 this canyon. 



The fauna in the axis is heavily dominated by shrimp 

 (1) in the depth interval between 500 and 1000 meters. This 

 part of the canyon has numerous exposures of hard substrate, 

 providing suitable habitats for these organisms. Along the 

 east wall of the axis the gorgonian Paramurioea grandis (4) 

 occasionally dominates the fauna or co-occurs with the shrimp. 

 Slightly deeper in the axis, the fauna is dominated by two 

 kinds of demersal fish, the eel Synaphobranahus kaupi (6) 

 and rattails (3) , and a species of cerianthid anemone (7) . 

 Below 1700 meters the ubiquitous brittle star Ophiomusium 

 lymani (8) dominates. The fauna of the east flank of 

 Oceanographer Canyon is almost totally dominated by the sponges 



