Morphological versus molecular approaches to evaluation of diversity and distribution of ciliates in marine sediments along environmental gradients

In this paper, we, for the first time, combined the microscopy observation and high-throughput DNA and cDNA sequencing of 18S rDNA to reveal the diversity and distribution of ciliates in marine sediments. Five sites with distinct environmental gradients in the Yellow Sea and the adjacent Bohai Sea were selected for the evaluation. We aimed to i) compare the differences between three inventories in terms of richness, dominant species, and community composition, ii) address the effects of extracellular DNA and DNA from dead cells and cysts on the molecular diversity, and iii) evaluate the performance of the three methods in detecting the shifts of communities along environmental gradients.