Some aspects of prey capture by Chaoborus larvae1

The effects of prey size, shape, and locomotion on capture, ingestion, and handling time were investigated in second‐, third‐, and fourth‐instar larvae of Chaoborus americanus and Chaoborus trivittatus from Eunice Lake, British Columbia. Before contact, densities and swimming speeds of predators and prey determine the number of interactions and hence availability. After contact is made, successful capture is determined largely by prey size and shape. Vulnerability increases as prey size decreases for both copepods and cladocerans. Although larvae are equally successful when striking at copepods or cladocerans, once contact with the prey is made copepods are handled much more efficiently than cladocerans of the same size. Size incompatibility between predator and prey is only important in prey capture at the extremes of the size ranges of both.