Diversity of copepod-associated prokaryotic microbiomes in the Yangtze River Estuary

Copepods serve as keystone components of marine food webs and microbial hotspots. In this study, we examined the prokaryotic microbiomes associated with five copepod species from the orders Calanoida and Cyclopoida in the Yangtze River estuary and its adjacent waters using 16S rRNA gene amplicon sequencing. Mesozooplankton samples were collected from 13 stations during 8-13 March and 11-16 July in 2019 using WP2 plankton net. Target copepod individuals were sorted on ice under stereomicroscope. Each DNA sample consisted of 30-60 adult individuals of the same copepod species collected from a single tow. The V4 region of the 16S rRNA gene was amplified using the primer pair 515F (5-GTGCCAGCMGCCGCGGTAA-3) and 806R (5-GGACTACHVGGGTWTCTAAT-3). Barcoded libraries were sequenced on a DNBSEQ-G400 platform to generate 200 bp paired-end reads.