Burrowing behaviour and species recognition predict colour pattern evolution in freshwater crayfishes

Area of Science:

• * Ecology and Evolutionary Biology
• * Animal Behavior
• * Biodiversity and Systematics

Background:

• * Organismal color patterns serve multiple functions, including crypsis, species recognition, and warning displays.
• * Freshwater crayfish exhibit diverse color patterns, but the ecological drivers are not fully understood.

Purpose of the Study:

• * To investigate the ecological and morphological factors influencing color pattern evolution in freshwater crayfish.
• * To determine if body size, congeneric sympatry, or burrowing behavior predict the presence of color patterning.

Main Methods:

• * Utilized a time-calibrated phylogeny for 393 freshwater crayfish species.
• * Employed phylogenetic logistic regression to analyze ecological predictors of color patterns.
• * Assessed the influence of body size, congeneric sympatry, and burrowing behavior.

Main Results:

• * Burrowing ecology and congeneric sympatry were significant predictors of color patterning.
• * Aquatic crayfish were 7.3 times more likely to have patterned coloration than semi-terrestrial species.
• * Color patterning increased with the number of sympatric congeners, suggesting a role in species recognition.

Conclusions:

• * Predation pressure and social interactions are key drivers in the diversification of crayfish color patterns.
• * The evolution of color patterns in crayfish is shaped by both ecological pressures and species interactions.
• * Phylogenetic signal was weak, indicating convergent evolution of these relationships.