Developmental Social Experience Changes Behavior in a Threatening Environment in Corydoras Catfish

Area of Science:

• Ethology
• Behavioral Ecology
• Neuroethology

Background:

• Coordinated antipredator responses are crucial for survival in many species.
• Social interactions during development can profoundly influence adult behavior.
• Gregarious species often rely on group dynamics for predator evasion.

Purpose of the Study:

• To investigate how developmental social experience affects antipredator behavior and group cohesion in the catfish, *Corydoras aeneus*.
• To compare the behavioral responses of catfish reared in mixed-age groups versus same-age groups when exposed to a startle stimulus.

Main Methods:

• Fish (*Corydoras aeneus*) were reared in two conditions: mixed-age (peers and adults) and same-age (peers only).
• Subadults from both conditions underwent a startle test to assess antipredator responses.
• Behavioral observations focused on tactile communication, activity levels, freezing, refuge-seeking, and group cohesion.

Main Results:

• Same-age reared (SAC) catfish exhibited increased tactile communication and reduced overall activity compared to mixed-age reared (MAC) catfish.
• SAC catfish showed stronger antipredator responses, including freezing and seeking cover, than MAC catfish.
• MAC fish tended to decrease group cohesion during startle events, while SAC fish tended to maintain or increase cohesion.

Conclusions:

• Developmental social context, specifically rearing with adults, can attenuate antipredator responses in *Corydoras aeneus*.
• Exposure to adult presence during development may lead to a reduced perception of threat.
• Social rearing environment is critical in shaping individual responses to environmental threats.