Macrofauna Associated with Echiuran Burrows: A Review with New Observations of the Innkeeper Worm, Ochetostoma erythrogrammon Leuckart and Rüppel, in Venezuela

Arthur Anker, Galena-Vantsetti Murina, Carlos Lira, Jonathan A. Vera Caripe, A. Richard Palmer, and Ming-Shiou Jeng (2005) Macrofauna Associated with Echiuran burrows: a review with new observations of the innkeeper worm, Ochetostoma erythrogrammon Leuckart and Rüppel, in Venezuela. Zoological Studies 44(2): 157-190. Because of their size and semipermanent nature, burrows of larger echiuran worms (phylum Echiura: Urechidae, Echiuridae, Bonelliidae, and Thalassematidae) host a remarkable variety of symbionts. Most symbionts appear to be commensals (occasionally with tendencies to kleptoparasitism), although at least 1 echiuran, Bonellia viridis, may in turn be a commensal of the soft rock-burrowing mudshrimp, Upogebia mediterranea. Commensal animals most frequently observed in echiuran burrows are bivalves (11 species in 8 hosts), polychaetes (mostly polynoids; 14 species in 8 hosts), brachyuran crabs (mostly pinnotherids and varunids; 16 species in 8 hosts), alpheid shrimps (6 species in 6 hosts), and copepods (3 species in 3 hosts). Some are facultative commensals (e.g., many polynoids and pinnotherids), but obligate and host-specific associations also occur, particularly among copepods and the loxosomatid entoprocts, Loxosomella spp. (with their associated gastropod predator, Sigaretornus planus). An alpheid shrimp, Alpheus barbatus, may also live in association with non-burrowing, crevice-dwelling echiurans. Other, less-frequent, echiuran commensals include polyclad flatworms (1 species), nemerteans (1 species), nematodes (2 species), entoprocts (2 species), * To whom correspondence and reprint requests should be addressed. Review Article