Ecology of ceriantharia (coelenterata, anthozoa) of the northwest Atlantic from Cape Hatteras to Nova Scotia

Abstract

Ceriantharia, tube dwelling anthozoans, were collected in grab samples and documented by direct observations and photographs from research submersibles on the continental shelf and slope off the northeast US coast (Cape Hatteras to Nova Scotia). Two species ((Cerianthus borealis Verrill and Ceriantheopsis 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 0 to 500 m and less abundantly from 900 to 2400 m. Ceriantharia habitats displayed an extreme range in bottom water temperature (summer maximum minus winter minimum) of from 8/sup 0/ to 16/sup 0/C, and had every sediment type, except 100% gravel and coarse shifting sand. Geographic and bathymetric zonation is attributed primarily to temperature 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 showmore » 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.« less