Eastern Bering Sea

SPONGES

Taxonomy: Phylum Porifera, class Demospongia

Species Representatives: Halichondria panicea, Suberites ficus, Mycale loveni

Distribution and Life History: The sponges (Phylum Porifera) are multicellular organisms containing a system of chambers and passageways that allow water to circulate constantly through the body. In many species, body size and shape is highly variable. Many sponges have a skeleton consisting of either calcium carbonate, silicon dioxide, or collagen fibers, or a combination of these substances (Barnes, 1980). Sponges can reproduce sexually or asexually. In sexual reproduction, a larva called a parenchymula often develops in the sponge and swims out to live freely for a day or two before settling to the substrate (O'Clair and O'Clair, 1998). Sponges are suspension feeders, creating currents that draw in plankton and organic detritus from the water column. In western Bering Sea, a diverse assemblage of sponges, bryozoans and hydroids were prime habitat for young-of-the-year red king crab (Paralithodes camtschaticus) (Tsalkina, 1969). The three species listed here occur in the SE Bering Sea, although they may not be the most common species or the most commonly taken in the NMFS trawl survey.

Halichondria panicea (barrel sponge) - Common north of the Alaska Peninsula, height to 30 cm. Large, thick-walled colony is highly variable in shape. (Kessler, 1985).

Suberites ficus (hermit sponge) - Common north of the Alaska Peninsula, length to 15 cm. Not attached to substrate. This sponge grows over a snail shell which it eventually dissolves. The shell/sponge is utilized by a hermit crab (Kessler, 1985).

Mycale loveni (tree sponge) - Common north of the Alaska Peninsula, height to 25 cm. Hard, tree-like skeleton surrounded by soft sponge (Kessler, 1985).