Foraging behavior of Macrobdella decora.

Abstract

This study investigated the sensory abilities and foraging behavior of the American medicinal leech (Macrobdella decora). Feeding responses to movement, temperature, amphibian skin secretions, and to different components of mammalian blood (serum, plasma, and whole blood) were tested. Results indicated that local water disturbances caused by intermittent movement of a blood source are an important sensory cue; an elevated relative temperature of the blood sources (compared to the surrounding water) also significantly increased foraging success. Further, a blood source that was both warmer than ambient water temperature and that exhibited quick, intermittent movement was most likely to be paraasitized. Chemosensation of both amphibian skin secretions and compounds within mammalian blood serum also appeared to play a major role in leech foraging behavior.