Body condition reveals hidden correlations between co-infection and behavior in sunfish

Area of Science:

• Behavioral Ecology
• Parasitology
• Animal Cognition

Background:

• Parasites influence host behavior and cognition, impacting host fitness and parasite transmission.
• Interactions between parasites, host behavior, and cognition are complex, particularly in wild populations.
• Host body condition is a crucial factor that can mediate parasite-host trait relationships.

Purpose of the Study:

• To investigate the relationships among parasite density, host body condition, personality (exploration, boldness), and cognition (aversive learning) in wild pumpkinseed sunfish.
• To determine if host body condition influences the observed associations between parasite infection and host traits.
• To explore the pathological effects of endoparasites on host behavior and cognitive performance.

Main Methods:

• Assessed personality traits (exploration, boldness) using repeatable behavioral assays in wild-caught pumpkinseed sunfish (Lepomis gibbosus).
• Quantified endoparasite density and host body condition as a proxy for fitness.
• Examined correlations between parasite density, body condition, and cognitive performance (aversive learning).

Main Results:

• Host exploration behavior was repeatable and negatively correlated with parasite density and decreasing body condition.
• The negative impact of parasite density on exploration was evident only in individuals with lower body condition.
• Aversive learning performance was not significantly affected by endoparasite co-infection.

Conclusions:

• Host body condition is essential for understanding parasite-host trait dynamics in natural populations.
• Parasite infection can have pathological effects on host behavior, particularly when host condition is compromised.
• Future studies should incorporate host health status to accurately interpret the complex interplay between parasites, behavior, and cognition.