Can fish species co-occurrence patterns be predicted by their trait dissimilarities?

Area of Science:

• Ecology
• Community Ecology
• Trait-Based Ecology

Background:

• Trait-based analyses are valuable for predicting species associations in communities.
• Previous studies often focused on limited species or regions, restricting broader ecological insights.

Purpose of the Study:

• To investigate how three key traits—body size, temperature preference, and trophic level—influence co-occurrence patterns among multiple fish species.
• To expand trait-based co-occurrence analysis beyond small-scale studies.

Main Methods:

• Utilized fish presence/absence data from 9,204 lakes in Ontario, Canada.
• Calculated Euclidean distances for body size, temperature preference, and trophic level between 2001 species pairs.
• Employed null models, multiple regression, and randomization tests to assess trait-co-occurrence relationships.

Main Results:

• Species temperature preference significantly correlated with co-occurrence, suggesting environmental filtering.
• Trophic level showed significant linear and quadratic relationships with co-occurrence, indicating segregation due to predation.
• Body size did not show a significant relationship with observed co-occurrence patterns.

Conclusions:

• Temperature preference and trophic level are significant drivers of fish species co-occurrence in Canadian lakes.
• Environmental filtering and interspecific competition (predation) shape community structure based on traits.
• Body size appears less influential on co-occurrence patterns compared to temperature and trophic level in this context.