Trait-based diet selection: prey behaviour and morphology predict vulnerability to predation in reef fish communities

Area of Science:

• Ecology
• Marine Biology
• Invasive Species

Background:

• Predator prey interactions are key to community dynamics.
• Species-specific prey selection data is limited due to prey variability.
• Predicting novel interactions requires a generalized approach.

Purpose of the Study:

• To develop a trait-based method for predicting predator diet selection across diverse prey assemblages.
• To identify general prey traits influencing vulnerability to predation, independent of species identity.
• To apply this method to invasive lionfish in the Indo-Pacific and western Atlantic.

Main Methods:

• Generated hypotheses on morphological and behavioral traits affecting lionfish predation risk.
• Used generalized linear mixed-effects models accounting for prey taxa relatedness.
• Analyzed two datasets: in situ observations and stomach content vs. reef availability comparisons.

Main Results:

• Prey body size, shape, water column position, and aggregation behavior significantly predict lionfish diet selection.
• Small, shallow-bodied, solitary fish resting near reefs are most vulnerable.
• Parasite cleaning behavior and nocturnal activity influence predation risk, with vulnerable traits increasing risk ~200-fold.

Conclusions:

• A trait-based approach provides robust insights into predator-prey interactions across different prey assemblages.
• This method yields similar results to traditional broad-scale analyses.
• Trait-based predictions can forecast impacts of changing predator-prey dynamics in various ecosystems.