Community organization and network stability of co-occurring microbiota under the influence of Kuroshio Current.

The Kuroshio Current structures environmental characteristics and biodiversity in the northwestern Pacific Ocean (NWPO), a region renowned for its dynamic oceanographic processes and rich marine ecosystems. However, the assembly and associations responses of prokaryotes and microeukaryotes to the Kuroshio Current remain largely unknown. Here, co-occurrence properties and stability of prokaryotic and eukaryotic microbiomes from three regions influenced by the Kuroshio: Kuroshio South of Japan (KSJ), Kuroshio Extension (KE), and the Kuroshio-Oyashio interfrontal zone (KOIZ) are systematically investigated. Microbiomes in the KE showed reduced phylogenetic distance and broader niche breadth than those in the KSJ and KOIZ. Microeukaryotic robustness was highest in the KE and lowest in the KOIZ, while prokaryotes showed the opposite pattern. Prokaryotic and microeukaryotic robustness and compositional stability formed complementary stabilizing and phylogenetic distance along vertical gradients in the KOIZ region, helping to maintain community and ecosystem stability. Prokaryotes and microeukaryotes formed complementary stabilizing under the influence of the Kuroshio Current. Overall, the network of prokaryotes was more stable than that of microeukaryotes, and microeukaryotes were more sensitive to environmental variations than prokaryotes. These results show how the Kuroshio Current influences the community organization and co-occurrence stability of prokaryotic and eukaryotic microbiomes, respectively, as well as their contrasting adaptability and survival strategies to environmental variation.