Phenotypic flexibility in background-mediated color change in sticklebacks.

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Phenotypic flexibility is crucial for adaptation in dynamic environments.
• Background-mediated color change is a key anti-predator adaptation in fish.
• Gaps exist in understanding the adaptive value, repeatability, and context-dependency of this trait.

Purpose of the Study:

• Investigate the adaptive value, repeatability, and phenotypic correlates of background-mediated color change.
• Examine context dependency in color change in response to predation risk.
• Compare color change abilities between two stickleback species.

Main Methods:

• Manipulative experiments exposing fish (Gasterosteus aculeatus and Pungitius pungitius) to different visual backgrounds.
• Quantification of color change from video recordings.
• Analysis of associations between color change and phenotypic traits (size, sex, boldness, parasite infection).

Main Results:

• Gasterosteus aculeatus showed greater color change than Pungitius pungitius.
• Color change was repeatable within G. aculeatus individuals and influenced by sex and boldness.
• Predation risk (simulated attacks, predator cues) enhanced color change in G. aculeatus.
• Parasite infection modulated, but did not eliminate, sex and boldness effects on color change.

Conclusions:

• Background-mediated color change is a repeatable and context-dependent phenotypic flexibility.
• Individual variation in color change is influenced by a combination of traits and environmental factors.
• This study provides novel insights into the adaptive significance and regulation of color change for predator avoidance.