Eastern Bering Sea

POLYCHAETE TUBE WORMS

Taxonomy: Phylum Annellida, class Polychaeta, subclass Sedentaria (mostly)

Species Representatives: Myriochele oculata, Sabella sp.

Distribution and Life History: Polychaete worms are members of the segmented worm Phylum Annellida. Most of the tube-dwelling, or tubicolous polychaetes, are members of the Subclass Sedentaria, while most of the free-living species are in the Subclass Errantia (Ushakov, 1955a, O'Clair and O'Clair, 1998). Only a few large, free-living polychaete species have been regularly identified on the NMFS trawl surveys in the SE Bering Sea. An estimated 194 species of polychaetes occur in the SE Bering Sea, including 22 tubicolous families containing about 50 species ⁽⁴⁾. The tubicolous species can build tubes of unadorned mud, sand, or parchment (often decorated with sand, shell, algae, hydroids), or of hardened calcium carbonate (O'Clair and O'Clair, 1998). The SE Bering Sea Sabellidae and Chaetopteridae range up to 15 cm in length and Maldanidae to 10 cm. The majority of the remaining species are probably small, at 0.5-1.5 cm ⁽⁴⁾. Most tubicolous polychaetes are either deposit feeders or filter feeders. Feder and Jewett (1981) stress the importance of Polychaeta in SE Bering Sea flatfish diets .

Tubicolous polychaetes are often found in dense mats. Along the north side of the Alaska Peninsula, these mats are refuge for small juvenile red king crabs (Paralithodes camtschaticus) (McMurray et al., 1984, Stevens and MacIntosh, 1991, Armstrong et al., 1993). Red king crab dependance on such refuge substrate appears to decline from age 1 to age 4.