Dissertation Research: Inducible Defenses and Plasticity in Tadpoles: Characterization of Chemical Alarm Cues

Cornell Univ - State: Awds Made Prior May 2010, Ithaca NY

Investigators

Abstract

Dissertation Research: Inducible Defenses and Plasticity in Tadpoles: Chracterization of Chemical Alarm Cues Dr. Thomas Eisner & Jacqualine Grant Many organisms go about their daily business unprepared for danger. However, some can anticipate hazards by cueing in on the environmental stimuli that presage peril. In the gray treefrog (Hyla versicolor) chemical alarm cues are released from the skin of injured tadpoles. These cues induce morphological and behavioral changes in conspecific tadpoles, changes that improve their ability to withstand future attacks. Specifically, the induction involves enlargement of the tailfin, and a simultaneous color change of the fin from nearly translucent to a mottled red and black. In its transformed state, the tadpole is said to be less vulnerable, because the gaudy tail deflects attacks away from the body itself. The transformed tadpole is also less active and, as a result, less conspicuous. The ecology of this phenomenon has received much attention, but so far the mediating chemicals remain unknown. This dissertation research is focused on characterizing those substances that trigger inducible defenses in gray treefrog tadpoles. The results will shed light on the evolution and ecology of morphological and behavioral plasticity.