Hydrodynamics of zooplankton: from mechanisms to rational behaviour
Andre Visser
DTU Aqua
Abstract:
As with all organisms, zooplankton are confronted by three overarching tasks; to feed, reproduce and avoid predation. Each of these is governed by an encounter rate; the rate at which an organism discovers food, finds mates, and is itself encountered by predators. Recent advances have illuminated the mechanisms that mediate individual zooplankton encounters – the key elements being an organism’s sensory ability, the nature of the signal by which detection is achieved (e.g. hydromechanical, chemical, visual), how these signals are attenuated by the environment (e.g. turbulence, light), and the organism’s behaviour (e.g. motility, migration, feeding mode). In terms of strategies, there exists some trade-off with regards the costs, benefits and risks inherent in a particular behaviour. For example, increased foraging effort will give greater access to resources, but also increased exposure to predation risk. Indeed, the fundamental nature of the life processes mediated by encounter rates suggests that there is a strong selection pressure on the abilities and behaviours, and those that are realized in nature are those that optimize an individual’s fitness in terms of evolutionary trade-offs.