Habitat complexity reduces aggression and enhances consumption in crayfish

We tested the hypothesis that increased habitat complexity would reduce intraspecific interactions among crayfish (Orconectes propinquus), and result in an increase in the consumption rate of prey at different crayfish densities. The effect of crayfish density, food level (trout eggs), and habitat complexity on prey consumption by crayfish was quantified in the laboratory. There was a significant difference in the consumption rate between different food levels. When food was scarce, almost all trout eggs were consumed regardless of crayfish density or habitat complexity. When food was unlimited, there was a significant positive linear relationship between eggs consumed per crayfish and habitat complexity. However, the relationship was not significant when trials without habitat were deleted from the analysis. We found that habitat complexity significantly reduced intraspecific aggression. Our findings suggest that a minimal amount of habitat complexity can reduce interactions among predators, ultimately resulting in increased prey consumption.