The Biology of the Stout Razor Clam Tagelus plebeius: I. Animal-Sediment Relationships, Feeding Mechanism, and Community Biology'

Six intertidal populations ofTagelus plebeius, the stout razor clam, and associated macroinvertebrates were sampled in the North Inlet estuary, near Georgetown, South Carolina.T. plebeius inhabited only stable sediments composed of greater than 2.0 % silts and clays and which were covered by a visible surface film of benthic microalgae. Gut contents, gill morphology, and behavior all indicated that this clam functioned as a suspension feeder obtaining its nutrition by filtering suspended particles from the water column. Maintenance of the siphon tubes and burrows was important to the survival of this organism.T. plebeius was quantitatively an important member of the infuana within its habitat, composing 93.0% of the biomass, but only 3.2% of the total number of individuals. Sediment stability, in addition to affecting the distribution ofT. plebeius, also had a significant role in determining the structure of invertebrate communities inhabiting the intertidal sandbars sampled. The stable muddy-sand sediments of lagoon areas supported a more diverse faunal assemblage than did the less stable sandy sediments of fringe areas of the same sandbar.