A-24. 



composed of a much more complex assemblage of a variety of 

 taxa and tropic types. 



The canyon fauna on the whole tends to follow the trend 

 of increasing importance of echinoderms with depth. The 

 middle depth zone from 650 to approximately 1400 meters is 

 dominated by corals and a variety of other taxa, whereas on 

 the slope it is dominated by fish. This difference could 

 well be due to the greater variety of substrate types and 

 higher nutrient flux available in canyon habitats. 



Several other notable exceptions to this trend were also 

 seen. During most of the shallow water DIAPHUS dives a 

 delicate white sea pen (unidentified at this time) was seen. 

 The percent of echinoderms in one dive at the head of Lydonia 

 Canyon is anomalously high. This reflects the large number 

 of individuals of the burrowing ophiuroid Amphilimna olivacea 

 seen during that dive. The dive transcript stated that the 

 submersible stayed in one place for a longer time than usual 

 and the ophiuroids started coming out of their burrows. Thus, 

 because of their burrowing habit they could be an important 

 constituent of the shelf fauna that would be overlooked in 

 photographic surveys. 



Two exceptions in the deeper part of the study area were 

 one dive at the Deep Water Dumspite #106 and one dive in the 

 deep axis of Hudson Canyon. The fauna seen on dive 666 at 

 DWD-106 was dominated by a small unidentified sea pen. A 

 major component of the fauna seen on dive 594 in the axis of 



