Meeting Abstract

P2.96  Sunday, Jan. 5 15:30  Revisiting the diet of worms JUMARS, PA; DORGAN, KM*; LINDSAY, SM; Darling Marine Center, University of Maine; Dauphin Island Sea Lab; School of Marine Sciences, University of Maine kdorgan@ucsd.edu

Polychaetes are numerically abundant and morphologically diverse, and dominate many infaunas. The classification of polychaete feeding guilds presented by Fauchald and Jumars (1979) has been widely used by ecologists and managers to characterize benthic communities and assess functional diversity as well as by biologists to explain morphologies, behaviors, and ecological roles of polychaetes. Over the past several decades, however, new taxa have been discovered and the phylogeny of annelids revised to include previously distinct groups not included in the original classification, thereby broadening the diversity of guilds within families. Stable isotopic analyses have provided new insights into trophic relationships, and these data have in many cases corroborated previous studies based on behavior or gut content analyses, but in a few consistently reject prior assignments. Recent advances in understanding of burrowing mechanics have highlighted the differences between sands and muds and altered interpretation of morphologies; e.g., tentacles and palps previously used to infer a surface deposit-feeding lifestyle may actually be used to feed on subsurface burrow walls. Advances in understanding of particle selection suggest that few if any deposit feeders are truly “non-selective.” Carnivores and deposit feeders have distinct gut morphologies, and digestion theory indicates a lower size limit for deposit feeding, an important generalization as data on meiofaunal feeding remain sparse. We present a revision of polychaete feeding guilds with highlights from a synthesis of new information, and we identify gaps in current understanding and emphasize the need for ongoing research and more frequent reexamination of feeding guilds.