Zooplankton diversity across three Red Sea reefs using pyrosequencing

John K Pearman,Anders Lanzã©N,Mohsen M El-Sherbiny,Ali M Al-Aidaroos,Xabier Irigoien

doi:10.3389/fmars.2014.00027

Abstract

Coral reefs are considered among the most diverse ecosystems on Earth, yet little is known about the diversity of plankton in the surrounding water column. Moreover, few studies have utilised genomic methods to investigate zooplankton diversity in any habitat. This study investigated the diversity of taxa by sampling 45 stations around three reef systems in the central/southern Red Sea. The diversity of metazoan plankton was investigated by targeting the 18S rRNA gene and clustering OTUs at 97% sequence similarity. A total of 754 and 854 metazoan OTUs were observed in the data set for the 1380F and 1389F primer sets respectively. The phylum Arthropoda dominated both primer sets accounting for ~60% of reads followed by Cnidaria (~ 20%). Only about 20% of OTUs were shared between all three reef systems and the relation between geographic distance and Jaccard Similarity measures was not significant. Cluster analysis showed that there was no distinct split between reefs and stations from different reefs clustered together both for metazoans as a whole and for the phyla Arthropoda, Cnidaria and Chordata separately. This suggests that distance may not be a determining factor in the taxonomic composition of stations.

Highlights

Coral reefs are known for harboring some of the highest biodiversity of benthic fauna and fish (Roberts et al, 2002)
operational taxonomic units (OTUs) clustering at 90, 95, 97, and 99% maximum linkage resulted in between 456 and 854 OTUs classified as metazoa for the composite dataset using 1389F and 355–795 for 1380F (Table 2)
– 935,577 www.frontiersin.org by UCHIME was employed to the datasets resulting from primer 1389F, leaving a slightly higher number of sequence reads (Table 1), but a lower total metazoan OTU richness from the total community (538 at 97% similarity, see Table 2)

Summary

INTRODUCTION

Coral reefs are known for harboring some of the highest biodiversity of benthic fauna and fish (Roberts et al, 2002). Little is known about the planktonic diversity in the water column associated with coral reefs This is true in the Red Sea, a narrow, semi-confined sea that combines high temperature (ranging from 25 to 32◦C), a deep basin (maximum depth of about 2300 m), oligotrophic conditions and high salinity (Raitsos et al, 2013). Extraction of bulk environmental DNA and the amplification of suitable genes, such as the nuclear small subunit (SSU) rRNA gene, has enabled whole communities to be studied This was via the construction of clone libraries and the subsequent Sanger sequencing of the inserts (Machida et al, 2009). In particular we investigate the similarity in the taxonomic composition of the reefs and whether there is any trend between similarity in stations and geographic distance

METHODS

RESULTS

Method

DISCUSSION