Diel rhythm and the microbiome in two zooplankton species

We used 16S rRNA V4 amplicon sequencing to study the microbiome of two freshwater zooplankton species to understand the interaction of host life history with microbiome composition. Daphnia magna is a large zooplankton species that primarily lives in fishless, shallow vernal pools, while Daphnia dentifera lives in a widely distributed range of ponds and lakes with and without fish. Daphnia dentifera exhibits a strong diel rhythm where it migrates to the freshwater body surface during the night to feed, and returns to the depths during the day when fish are more active. We sampled both species at day and night time points to understand if there were 1) differences in composition across the two species, and 2) differences within a species at different time points.