SHEPARD ET AL.: ECOLOGY OF CERIANTHARIA 



IA 



O 



I 

 a. 



o 



x 



< 



cc 



Id 



IB 



IA 



SUBSTRATE 



152 M 



151 M 



i i i i — i — T — r 

 200. 250. 



PHOTO # 



— i — i — i — r 



400. 



0.0 



0.6* 

 TRANSECT LOCATION (KM) 



1.2 



Figure 7.— One example, from 1980 Johnson-Sea-Link dives 15 and 16 in Lydonia Canyon, of the photograph-by-photograph transect 

 profiles of Ceriantharia abundance constructed for quantitative submersible dives during which Ceriantharia density exceeded 0.1 

 m" 2 dive" 1 , at depths of less than 400 m. Substrate codes: 1 - sand base, IA - silt veneer, IB - greater than 5% gravel cover. 

 A permanent station marker (37 khz pinger) was located at 0.6 km into the transect, as denoted by the asterisk. 



asteroids on gravel-sand, and shell-less hermit crabs, 

 Catapagurus sp., on silt-sand. Galatheids were also 

 observed on silt-sand sediments, often near cerian- 

 tharian tubes. A qualitative observation made on 

 several submersible dives was that Ceriantharia 

 "forests" (aggregations) were often associated with 

 rises in seafloor topography. 



Functional Role 



Figure 8 (data from 1979 Nekton Gamma dive #3 

 in Block Canyon) shows Cerianthid C frequency of 

 occurrence and number of associated species (diver- 

 sity) plotted by photographic frame. The substrate 

 throughout the dive was a low-relief silt-clay, and 



-i — i — i — i — | — i — n — | V i — i — | — i — i — i — | — i — i — i — | — i- 

 20 40 60 80 100 120 140 160 



PHOTO n 



Figure 8.— Cerianthid C abundance and diversity (number of species) of associated 

 fauna along a 1.0 km photographic transect from 1979 Nekton Gamma dive #3. 

 Each data point represents the sum of 5 adjacent photographic frames: species 

 diversity increased significantly in areas with Ceriantharia (Mann-Whitney test, 

 P < 0.01). 



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