In BC, the tan cup corals Caryophyllia alaskensis and C. arnoldi are deeper-dwelling relatives of the cup coral Balanophyllia elegans. Like Balanophyllia elegans, these other cup corals likely feed on small crustaceans and other organisms in the plankton. As with all cnidarians, including sea anemones and other corals, guts of cup corals are simple sacs with only a single opening, the mouth. With no anus, what happens to undigested food residues? They are simply pushed back out the mouth. In "true" corals consisting of a colony of polyps, the individual polyps are interconnected, and food energy and nutrients are shunted from "prey-rich" polyps to "prey-poor" polyps but, in this regard, cup corals are on their own.
This is a demersal species found in the northern Pacific (Sealifebase 2011). In British Columbia, it is reported from along the coast.
For more information see A SNAIL'S ODYSSEY. Use the drop-down menu to access topics on corals.
Note Author: Tom Carefoot, Department of Zoology, University of British Columbia