Heritable differences in schooling behavior among threespine stickleback populations revealed by a novel assay

Area of Science:

• Behavioral biology
• Evolutionary biology
• Ethology

Background:

• Schooling behavior is a complex social phenomenon crucial for fish survival and evolution.
• Previous research has primarily focused on schooling as a group-level behavior, lacking individual-level analysis.
• Investigating individual mechanisms is key to understanding the evolution and performance of schooling.

Purpose of the Study:

• To develop and apply a novel assay for quantifying individual fish schooling behavior.
• To compare schooling tendencies between marine and freshwater benthic threespine sticklebacks.
• To explore the heritability and underlying stimuli of schooling behavior differences.

Main Methods:

• Development of a "model school assay" to standardize social conditions.
• Behavioral testing of threespine sticklebacks (Gasterosteus aculeatus) from marine and freshwater benthic populations.
• Analysis of association, parallel swimming, and shelter preference.

Main Results:

• Marine sticklebacks showed significantly higher association and parallel swimming with model schools compared to benthic sticklebacks.
• Population-level differences in schooling tendency were demonstrated to be heritable.
• Differential preferences for social vs. non-social and moving vs. stationary shelters were observed between populations.

Conclusions:

• Marine sticklebacks possess a stronger schooling tendency than benthic sticklebacks, indicating adaptive divergence.
• Heritability of schooling tendency suggests a genetic basis for this social behavior.
• Differences in schooling are associated with distinct sensory preferences, offering insights into evolutionary drivers.