43. 



taxa observed in this canyon. Examination of this table, 

 again, points to the availability of hard substrate deter- 

 mining the occurrence of various taxa. The middle depth 

 zone is dominated by organisms that require or prefer hard 

 substrates. These are shrimp and sponges. In the lower 

 depth zone the ophiurid Ophiomusium lymani is the most 

 abundant species, however, all of these individuals were 

 seen in one area, between 17 and 18 00 meters in the axis 

 of the canyon. 0. lymani is also the dominant component of 

 slope fauna at comparable depths. Attached forms common in 

 Oceanographer Canyon in this depth zone are the gorgonians 

 Paramurioea grandis and Aoanthogovgia avmata and sponges. 



The differences between the fauna observed in this study 

 when compared to that commonly found on the slope are in the 

 greater proportions of taxa requiring or preferring hard 

 substrates. Table VII is a listing of these organisms ranked 

 by their relative contribution to the total hard substrate 

 fauna in their respective depth zone. The large white anemone 

 accounts for the majority of the attached fauna in the 

 shallow zone of Baltimore Canyon. Shrimp and several anemones 

 are the dominant hard substrate forms in the middle depth zone 

 of this canyon. The hard substrates in the shallow and middle 

 depths of Lydonia Canyon are also dominated by anemones, with 

 shrimp becoming increasingly important at greater depths. Also 

 many corals are found on the exposed hard substrates in this 



