Mechanical vibrations from tadpoles' flapping tails transform salamander's carnivorous morphology.

Area of Science:

• Developmental Biology
• Ecology
• Evolutionary Biology

Background:

• Organisms often display rapid morphological plasticity in response to environmental cues like predators or prey.
• Chemical cues are the most common inducers of these distinct morphs, influencing both behavior and morphology.

Purpose of the Study:

• To investigate the role of hydraulic vibrations as a cue for inducing carnivorous morphology in larval salamander Hynobius retardatus.
• To determine if mechanical vibrations alone can trigger the development of a broad-headed, carnivorous morph.

Main Methods:

• Exposing larval Hynobius retardatus to hydraulic vibrations generated by anuran tadpole tails.
• Utilizing mechanical vibrations from artificial tail-like vinyl fins as a control for non-biological induction.
• Observing and quantifying the resulting morphological changes, specifically the development of a broad-headed morph.

Main Results:

• Hydraulic vibrations from tadpole tails successfully induced a distinct carnivorous morphology in Hynobius retardatus larvae.
• Mechanical vibrations from vinyl fins also induced the broad-headed morph, demonstrating that biological cues are not essential.
• The induced morph exhibited enhanced prey capture and handling capabilities.

Conclusions:

• Hydraulic vibration is a significant proximate cue for inducing carnivorous morphology in larval salamanders.
• Morphological plasticity can be induced by non-chemical, mechanical stimuli, broadening our understanding of developmental plasticity.
• This finding offers a novel perspective on the mechanisms driving rapid adaptive morphological changes in response to environmental pressures.