The functional morphology and feeding behavior of Malacoceros indicus were studied in a coarse, coralline sand habitat at Lizard Island, North Queensland, Australia. Unlike other spionid polychaetes, the tentacular feeding palps were never observed extended above the sediment-water interface to feed on suspended particles. Spionids that switch between deposit-feeding and suspension-feeding modes typically have three or four functional groups of cilia on their palps. In contrast, M. indicus had a single functional group, the frontal cilia lining the food groove of the palp. The restriction of feeding behavior to deposit-feeding may be behaviorally constrained due to the absence of abundant suspended particles and by the lack of easily resuspended fine particles in the habitat. Gut content analyses indicated no selection of deposited particles compared to ambient sediment composition; however, particles in the size range selected by other spionid species were not present in the ambient sediments.

The distribution of the macrobenthic infaunal community within the upper 25 cm of the sediment was studied at 16 stations in the lower Chesapeake Bay. Stations were located from the tidal freshwater to the polyhaline zone of major tributaries (James, York and Rappahannock Rivers) and in the polyhaline portion of the lower bay mainstem. Profiles for total number of individuals, total ash-free dry weight biomass and species encountered with depth were calculated. Except for the deep dwelling bivalve, Macoma balthica , tributary macrobenthic communities had a shallow depth distribution compared to the mainstem sites which were found in generally coarser sediments in the higher salinity region of the estuary.

AbstractThe distribution, abundance, and species composition of subtidal macrobenthic invertebrates of the lower Chesapeake Bay and the inner continental shelf off the mouth of the bay were studied. The benthos of the lower bay was sampled on two bay‐wide transects sampled once in June 1978. The benthos of the inner shelf was sampled five times per year from 1979 through 1981. Data from this study were compared with data from previous studies of estuaries and the inner shelf of the mid‐Atlantic Southeastern U.S.

The feeding behavior of six species of spionid polychaetes (Paraprionospio pinnata (Ehlers), Polydora ligni Webster, Scolecolepides viridis (Verrill), Spiophanes bombyx (Claparede), Spio setosa Verrill, and Streblospio benedicti Webster) from the Chesapeake Bay was studied. All species fed on both suspended (including resuspended) and deposited particles and increased their feeding rate, as indicated by fecal production, in the presence of a current transporting suspended particles. Although all six species have the same anatomical structures for food gathering, a wide variety of food particle collection behaviors was observed. Palp movement patterns varied from species to species as well as with the size, the habitat type of collection, and the presence of suspended particles. Factors not directly related to feeding are probably as important in understanding the observed distributional patterns. Food availability and competitive interactions affected small-scale movements of individuals.

AdultScolecolepides viridis were collected by nocturnal plankton tows in the Lafayette River, Norfolk, Virginia. All adults (40–70 mm) were filled with ripe gametes. Swimming individuals were collected only at night on ebb tides. Large (36–60 setigers) post-metamorphic worms were also collected in the plankton. The occurrence of down estuary adult movement is used to explain paradoxical information concerning this species within estuary distribution and early development.