Feeding experiments on Penilia avirostris dana (cladocera: crustacea)

Feeding in the marine cladoceran, Penilia avirostris Dana, was investigated using plastic micronic beads as a controlled particle source. The range of bead size ingested by P. avirostris was largely limited to diameters of 20 μm and below, perhaps a competitive advantage in nature, was found that: (1) as the concentration of beads increased, the number of beads ingested increased: (2) as the number of P. avirostris increased, the number of beads ingested increased: and (3) the number of beads ingested also increased with body size. The size of P. avirostris , however, did not appear to limit the size of bead ingested, while larger sized animals may be better competitors for particles.