From microbes to animals: a review on prey choice and prey-predator dynamics across organismal scales.

Predator-prey interactions are intricately linked to ecological systems, from micro-organisms to large animals. Most predator-prey studies use simplified pairwise interactions, constraining our ability to identify general principles. Here, predator-prey choices are examined across scales and levels of environmental complexity. We review current knowledge and emphasize the diversity and complexity of predator-prey systems, point to challenges in integrating them, and propose a framework that could benefit predictive modeling for ecosystem functioning and resilience. To do so, we compare the tools, mechanisms, and strategies deployed by micro- and macro- predators and prey defenses to show that commonalities become identifiable, and suggest structural and functional links between micro- and macro-scales. This provides arguments for both descriptive, and mathematical models. We propose that the use of microbial predators like the Bdellovibrio and like organisms can greatly advance the integration of experimental and mathematical modeling research, as they can provide robust empirical observations of predator-prey interactions tested under multiple conditions and levels of complexity. This facilitates model development, in turn leading to new hypotheses. We conclude by showing examples of current developments, that predator-prey interaction-based knowledge has the potential to provide novel medical tools and to improve environmental and agricultural management.