ECOLOGY OF CERIANTHARIA (COELENTERATA, ANTHOZOA) OF 

 THE NORTHWEST ATLANTIC FROM CAPE HATTERAS TO NOVA SCOTIA 



Andrew N. Shepard, 1 Roger B. Theroux, 2 Richard A. Cooper, 1 

 and Joseph R. Uzmann 2 



ABSTRACT 



Ceriantharia, tube dwelling anthozoans, were collected in grab samples and documented by direct obser- 

 vations and photographs from research submersibles on the continental shelf and slope off the northeast 

 United States coast (Cape Hatteras to Nova Scotia). Two species [{Cerianthus borealis Verrill and Cerian- 

 theopsis americanus (Agassiz)] were identified from grab samples and four species, probably including 

 C. borealis, were observed from submersibles. 



Ceriantharia distribution in relation to latitude, depth, temperature, and sediments was examined. 

 They occurred throughout the study area, abundantly at depths of to 500 m and less abundantly from 

 900 to 2,400 m. Ceriantharia habitats displayed an extreme range in bottom water temperature (sum- 

 mer maximum minus winter minimum) of from 8° to 16°C, and had every sediment type, except 100% 

 gravel and coarse shifting sand. Geographic and bathymetric zonation is attributed primarily to tem- 

 perature and secondarily to food supply and substrate type. 



Ceriantharia distribution patterns, in submarine canyon heads at depths of <400 m, were determined 

 from photographic transects run with submersibles; observed patchiness may be related to local differences 

 in food supply, sediments, and microtopography. 



The motile megafauna associated with Ceriantharia "forest" areas and the infauna and epifauna 

 inhabiting ceriantharian tubes were evidence to show that tubes may enhance local species diversity and 

 abundance in featureless soft-bottom areas by 1) attracting motile species seeking cover and 2), acting 

 as a stable, elevated substrate for tubiculous and suspension feeding macrofauna. 



The possibility of exploitation of energy reserves 

 beneath the northwest Atlantic outer continental 

 shelf and slope has prompted many new studies and 

 the reexamination of past investigations for baseline 

 information on the region's seafloor communities. 

 Research submersible studies of potential oil lease 

 tracts identified "indicator species" for assessing 

 environmental changes owing to drilling activities. 

 We considered Ceriantharia suitable for this purpose 

 because they were abundant, passive suspension 

 feeders, and nonmobile. Literature searches re- 

 vealed that very little has been published on the 

 Ceriantharia species occurring from Cape Hatteras 

 to Nova Scotia. This is surprising in light of the 

 group's significant contribution to the benthic bio- 

 mass of the region (Wigley and Theroux 1981) and 

 the important functional role [the effect a species 

 has on the distribution and abundance of other 

 residents (Sutherland 1978)] Ceriantharia may have 

 in structuring communities inhabiting featureless 

 soft-bottom substrate (O'Connor et al. 1977). 



Woods Hole Laboratory, Northeast Fisheries 

 Center (NEFC), National Marine Fisheries Service 

 (NMFS), personnel have reported on the general 

 composition and distribution of invertebrate fauna 

 of the New England and Mid- Atlantic Bight con- 

 tinental shelf and slope (e.g., Wigley and Theroux 

 1981; Theroux and Wigley 1984 3 ; Cooper et al, in 

 press). Data on Ceriantharia were collected during 

 ecological studies pertaining to various kinds of 

 demersal fishes and benthic invertebrates: 1) a grab 

 sample survey (Fig. 1) done from 1955 to 1969 

 (Shepard and Theroux 1983 4 ), and 2) observations, 

 photographs, and limited sample collections from 

 research submersible studies. Dredge and trawl data 

 were available (Shepard and Theroux fn. 4), but not 

 analyzed since deep burrowing Ceriantharia (some- 



'NOAA National Undersea Research Program, University of 

 Connecticut, Avery Point, Groton, CT 06340. 



2 Northeast Fisheries Center Woods Hole Laboratory, National 

 Marine Fisheries Service, NOAA, Woods Hole, MA 02543. 



3 Theroux, R. B., and R. L. Wigley. 1984. Quantitative com- 

 position and distribution of macrobenthic invertebrate fauna of the 

 New England Region. Unpubl. Manuscr. Northeast Fisheries 

 Center Woods Hole Laboratory, National Marine Fisheries Ser- 

 vice, NOAA, Woods Hole, MA 02543. 



"Shepard, A. N., and R. B. Theroux. 1983. Distribution of 

 Cerianthids (Coelenterata, Anthozoa, Ceriantharia) on the U.S. 

 East Coast Continental Margin, 1955-1969: Collection data and 

 environmental measurements. Lab Ref. Doc. 83-12, 24 p. North- 

 east Fisheries Center Woods Hole Laboratory, National Marine 

 Fisheries Service, NOAA, Woods Hole, MA 02543. 



Manuscript accepted September 1985. 

 FISHERY BULLETIN: VOL. 84, NO. 3, 1986. 



625 



