Co-cultured non-marine ostracods from a temporary wetland harbor host-specific microbiota of different metabolic profiles

Rapid development of high-throughput sequencing methods and metagenomics revealed a diverse world of microbiota associated with multicellular organisms. Although recent discoveries indicate that freshwater invertebrates are hosts for specific bacteria, it is still unknown if this specificity is driven by host-derived factors or by the environment, especially in animals with diapause in ephemeral habitats, where parents and offspring are separated in time and space. In this work, using both low-throughput molecular approach and Next-generation sequencing of 16S ribosomal RNA gene, we present a taxonomic analysis of bacteria associated with two species of non-marine ostracods Sclerocypris tuberculata and Potamocypris mastigophora raised from diapausing eggs and co-cultured in laboratory conditions. Our analysis showed that despite sharing the same environment, each ostracod host developed distinct bacterial communities. The major difference was caused by the dominance of the family Comamonadaceae (Betaproteobacteria) in P. mastigophora and the Aeromonadaceae (Gammaproteobacteria) in S. tuberculata . Furthermore, prediction of metabolic pathways in metagenomes, revealed that microbiota of P. mastigophora exhibit higher number of sequences associated with the membrane transport and xenobiotics biodegradation and metabolism. Our study not only provides an insight into microbiota of non-marine ostracods but also shows that different ostracod species host functionally distinct bacterial communities.