Eastern Long‐toed Salamander (Ambystoma macrodactylum columbianum) Larvae Recognize Cannibalistic Conspecifics

Abstract

AbstractLarval eastern long‐toed salamanders, Ambystoma macrodactylum columbianum, exhibit trophic polymorphism whereby some individuals (referred to as cannibal morphs) possess a cannibalistic morphology and others (referred to as typical morphs) do not. In a series of laboratory experiments, we documented that typical morphs show an antipredator response when exposed to cannibal morphs but not when exposed to other typical morphs. The antipredator response of the typicals was not dependent on the cannibals being fed conspecifics, as has been shown in other predator‐prey systems. In our experiments, the typicals responded regardless of whether the cannibals had been fed a diet of conspecifics or live Tubifex. Further experiments also showed that in the absence of visual cues, typicals still responded with an antipredator response. However, when only visual cues were available, typicals failed to exhibit a response. This suggests that chemical and/or mechanical cues are of prime importance in cannibal recognition by long‐toed salamander larvae.