Importance of predatory infauna in marine soft-sediment communities

Ambrose (1984a) suggested that a 3-way interactive model should be applied to marine infaunal communities having the levels of epibenttuc predators, predatory infauna and nonpredatory infauna. It is shown that the 3-level interactive model incorporates the implicit, unstated assumption that epibenthlc predators preferentially prey on predatory infauna. A review of the literature reveals that this assumption is not true. The assumption of predatory infauna being more susceptible to epibenthic predation is challenged. Reanalysis of the caging studies analyzed by Ambrose with a more ngorous and conservative classification of predatory and nonpredatory lnfauna provides no support for the proposed model. The application of the proposed 3-level interactive model to marine infaunal communities is not justified.