Evolutionary shift towards lateral line dependent prey capture behavior in the blind Mexican cavefish

Area of Science:

• * Evolutionary biology
• * Sensory neuroscience
• * Ichthyology

Background:

• * Feeding strategies rely on integrating visual, chemical, and mechanical sensory information.
• * Environmental factors and food availability shape sensory and morphological traits in fish feeding.
• * Mexican cavefish (Astyanax mexicanus) exhibit significant sensory-behavioral changes, but their impact on feeding is unclear.

Purpose of the Study:

• * To investigate evolved differences in prey detection and feeding behavior in Mexican cavefish larvae.
• * To determine the role of lateral line sensitivity in cavefish prey capture.
• * To understand how the loss of vision influences multi-modal sensory behaviors.

Main Methods:

• * Comparative behavioral analysis of larval cavefish and surface fish feeding.
• * Manipulation of light conditions to assess sensory modality reliance.
• * Experimental ablation of the lateral line system to evaluate its functional importance.

Main Results:

• * Cavefish strike prey at wider angles in light but this difference reduces in darkness compared to surface fish.
• * Cavefish exhibit a greater strike distance, indicating enhanced prey detection and capture at longer ranges.
• * Lateral line ablation significantly impairs prey capture in cavefish under all conditions, and in surface fish only in darkness.

Conclusions:

• * Cavefish display an evolutionary shift towards increased reliance on the lateral line for prey capture.
• * This study provides a model for examining sensory compensation following visual system loss.
• * Evolved lateral line sensitivity is crucial for cavefish feeding behavior in the absence of vision.