Intraspecifîc discrimination of amphipod prey by a freshwater leech through mechanoreception

Abstract

We recorded the vibrations produced by different age-classes of swimming amphipods (Hyalella montezuma). Adult H. montezuma produced a more continuous signal, while juveniles produced an intermittent signal (22 – 28 pulses/s). The leech Erpobdella montezuma demonstrated a significantly greater attack response for playback recordings of juvenile amphipod prey. Intermittent signals produced from an electronic generator were also attacked by E. montezuma at a significantly greater rate than more continuous electronic signals. This provides evidence that E. montezuma can distinguish between juvenile and adult H. montezuma prey by mechanoreception.