Biological rhythms appear to help organisms coordinate key physiological processes with the earth’s daily and seasonal rotations. The genetic and molecular mechanisms that govern daily (circadian) and other types of biological rhythms are relatively well characterized. Yet, scaling up what we know at the cellular and molecular level to the individual-, population-, or community-level remains challenging. This gap hinders our understanding of how biological rhythms shape the ecology and evolution of natural systems. Here, we examine how variation in circadian rhythms of a zooplankton host — which exhibits some of the most massive diurnal vertical migrations in lakes and ocean’s around the world — affects resource acquisition, within-in host energetics, immune function, and susceptibility to a fungal pathogen (Metschnikowia bicuspidata). We then link these within-host processes to epidemiologically-relevant parasite traits (load, transmission).
Results/Conclusions
We found strong circadian patterns of resource acquisition that correlate to the crepuscular migrations and nocturnal foraging patterns of the host. These patterns substantially alter exposure and contact rates with parasites as well as the host’s ability to cope with and fend off disease. These findings join others suggesting that links between the biological rhythms of hosts with host defense and disease opens new frontiers for understanding, predicting, and managing disease in both wildlife and human systems.