Comparison of Gravisensing Organs in Different Planktonic Organism – From Evolution to Life Support Systems

Abstract

Bioregenerative life support systems are critical components for long-term human space travel, as they provide processes for establishing the components for basic consumable biomass production, and therefore saving costs for transport and technical equipment otherwise necessary. The high reproductive output and the essential role in aquatic foodwebs suggest especially aquatic zooplankton species to be suitable for such bioregenerative life support systems. Considering the broad range of gravity-perception systems - from sensilla based structures up to statocyst systems - there is still a considerable lack of knowledge for zooplankton species in both marine and freshwater species regarding this aspect. Hence, the purpose of the current project is to develop a highly representative comparison of gravity-perception systems in selected zooplankton organisms with special emphasis on their evolutionary history. In addition, sensitive windows for graviperception in ontogeny as well as thresholds of graviperception will be analysed in selected organisms. Moreover, ground based studies will be performed to investigate the effects of reduced gravity on life history of the selected zooplankton species. The outcome will not only foster the selection of zooplankton species for future live support systems. Furthermore, it will significantly increase knowledge on the evolution of graviperception in aquatic ecosystems where gravity is often the only reliable cue for orientation, and may therefore elucidate general gravity-related mechanisms valid for other organisms as well.