An Antarctic Soft-Sediment Community Oliver and Slattery (1985) studied a rare soft-bottom community in McMurdo Sound, Antarctica. This was composed primarily of burrowing and tube-building polychaete worms and small crustaceans that occurred in densities of over 100,000 individuals per square meter. This dense assemblage was divided into three faunal groups of species that had similar characteristics. The three groups were canopy, under-story, and subsurface (Figure 5.45). The canopy was dominated by the anemone Edwardsia and consisted primarily of suspension feeders. The understory included mainly mobile crustaceans that were deposit feeders and predators. The subsurface species group was composed primarily of tube-dwelling polychaetes that were mainly deposit feeders.