Noncommercial benthic fauna

Eastern Bering Sea


Inflated colony of the soft coral Gersemia sp.
from the SE Bering Sea.

Phylum Cnidaria, class Anthozoa, subclass Octocorallia, order Alcyonacea,
family Nephtheidae

Species: Gersemia rubiformis and/or G. Fruticosa

Distribution and Life History: Gersemia is a colonial soft coral in the cnidarian Class Anthozoa, which also includes the sea anemones, sea pens, and other corals. Soft corals of this genus are found worldwide from the Arctic to the Antarctic. Most corals reproduce asexually as well as sexually. The sexes are usually separate. A planula larvae is produced which is usually not dispersed very far from the parent colony (Cimberg et al., 1981). Some Gersemia contain bioactive compounds that deter predatory sea stars and fishes (Slattery and McClintock, 1995).

Gersemia rubiformis and/or G. fruticosa - Gersemia in the SE Bering Sea belong to either one of, or both of these species. These species are distributed in the north Atlantic and in the Pacific from the Bering Sea south to California (Koltun, 1955, Gotshall, 1994). Within Alaska, Gersemia has the widest distributional, temperature, and substrate preference range of all Alaskan corals (Cimberg et al., 1981). Kessler (1985) calls it common north of the Alaska Peninsula. Gersemia looks entirely different out of water than it does when it is inflated in water. When inflated, groups of small polyps form thick, soft, red lobes in colonies that can reach a height of about 25 cm (Koltun, 1955). When contracted, the colony has a brain-like appearance and is considerably smaller. Colonies are found attached to stones or shell. Gersemia is thought to be a plankton feeder (O'Clair and O'Clair, 1998).