ABSTRACT
Spioniform polychaetes are sedentary, tubicolous worms that feed and build tubes using a pair of prehensile palps, usually grooved, that arise dorsolaterally from the peristomial segment. Adult morphology varies widely between the spioniform families and often within them. Seven families are classified within Spionida as delineated by Rouse and Fauchald (1997): Apistobranchidae, Chaetopteridae, Magelonidae, Poecilochaetidae, Spionidae, Trochochaetidae, and Uncispionidae. These polychaetes, especially those genera and species normally included in the Spionidae, are among the most familiar invertebrates of coastal benthic communities. Spioniforms have been the subject of numerous studies including comprehensive reviews of reproduction (Soderstrom 1920; Franzen 1956; Blake and Arnofsky 1999), development (Hannerz 1956; Blake 1969), anatomy (Orrhage 1964), and systematics (Foster 1971; Blake and Kudenov 1978; Blake 1996).
