title: CB1
design: Library preparation and amplicon high throughput sequencing followed the 18S Metagenomic Sequencing Library Preparation protocol from Illumina (https://support.illumina.com/). 18S rRNA genes were amplified using universal eukaryotic primers for the V4 region. PCR reactions and library construction were performed at Magigene (Magigene Biotechnology Co. Ltd., Guangzhou, China) and high-throughput sequencing of 18S rRNA genes was performed on an Illumina Nova6000 platform (paired-end 250-bp mode), following the manufacturers guidelines.