A comparison of microeukaryote communities inhabiting sponges and seawater in a Taiwanese coral reef system

Abstract

Purpose: Assess microeukaryote community composition in seawater and sponge samples from Taiwanese coral reefs. Methods: In the present study, we used Illumina sequencing to explore the microeukaryote communities of seven biotopes (six sponge species and seawater) sampled in the Penghu archipelago of Taiwan. Result: Microeukaryote communities were dominated by Dinoflagellates with Dinophyceae and Syndiniales well represented in all biotopes. Other abundant taxa included metazoa, red and green algae and Radiolaria. The only significant differences were a significantly higher relative abundance of Picobiliphyta and Stramenopiles_X in seawater and Metamonada in the sponge Acanthostylotella cornuta. There was also a significant difference in composition among biotopes with samples from sponges and seawater forming distinct clusters. There was, however, no congruence between prokaryote and microeukaryote community composition. After removing all OTUs < 100 sequences, more than 90% of remaining OTUs representing > 99.5% of sequences were shared between sponge and seawater samples. Conclusion: This data in the present study would appear to suggest that marine microeukaryote communities in sponges are largely derived from the surrounding seawater. Abundant OTUs were also related to organisms previously retrieved from seawater. A number of these OTUs though had relatively low sequence similarity to organisms in GenBank suggesting that more research of the microeukaryote communities in the Penghu archipelago may yield novel organisms in this relatively unexplored area.