Multigene Assessment of Biodiversity of Diatom(Bacillariophyceae) Assemblages from the Littoral Zone of the Bohai and Yellow Seas in Yantai Region of Northeast China with some Remarks on Ubiquitous Taxa

Abstract

Diatoms are important contributors to the benthic microeukaryote flora. This manuscript lays the foundation for future metagenomic and environmental sequencing projects off coastal China by curating diatom DNA sequences from the Yantai region of the Bohai and Yellow Seas ( Northeast China) . These studies are based on cultures established from samples collected in different seasons from marine littoral and supralittoral zones in 2013 and 2014. Thirty-six diatom strains were cultured successfully and identification of these clones was determined by light and scanning electron microscopy( LM and SEM) and DNA sequencing of the nuclear-encoded small subunit ribosomal RNA ( SSU) and chloroplast-encoded rbcL and psbC genes. The strains primarily represent raphid pennate genera, such as Amphora, Amphora ( Oxyamphora) , Caloneis, Diploneis, Halamphora, Navicula, Nitzschia, Parlibellus, Pleurosigma, Surirella and Tryblionella. When the DNA markers from these strains were analysed in a multi-gene phylogeny, we found that some clones-particularly within the genera Amphora, Navicula and Nitzschia-show greater than expected genetic diversity despite their very similar morphology and morphometrics. We also compared the molecular and morphological identities of several seemingly ubiquitous marine littoral taxa in the genera Amphora and Nitzschia from the Indian Ocean and Atlantic Ocean, the Red Sea and Adriatic Sea to their Yellow Sea counterparts.

Diat.barcode, an open-access curated barcode library for diatoms

“…Many also come from the UK-barcoding project. Similarly, a number of newly sequenced strains from the genus Nitzschia have been added thanks to studies in marine coastal environments ( 69,70 and 45 ) and from the UK-barcoding project. A major taxonomic study of the Surirellales and Rhopalodiales orders also resulted in many new taxa being sequenced, leading to a major reevaluation of the taxonomy, with creation of new genera and transfers of taxa 71 .…”

Majewskaea gen. nov. (Bacillariophyta), a new marine benthic diatom genus from the Adriatic Sea

“…Riaux-Gobin et al (2012) reported that the genus Karayevia is highly heterogeneous based on several features such as the presence/absence of areolae on the SV mantle and the highly variable stria structure within the emended genus. Witkowski et al (2016) contested subsequently the inclusion of Kolbesia in Karayevia when they described a new Kolbesia species, K. sinica Krzywda et al based on morphological and molecular data. According to them, the genus Karayevia consists of species having striae composed of small, rounded areolae such as K. clevei, whereas Kolbesia possesses striae composed of (post) macroareolae covered externally.…”

Morphological diversity and phylogeny of the diatom genus Entomoneis (Bacillariophyta) in marine plankton: six new species from the Adriatic Sea

“…On one side, the generally complex three-dimensional structure and light silification of planktonic Entomoneis frustules requires detailed light and electron microscope observations of the valve and girdle elements for accurate species identification. On the other, molecular data for phylogeny reconstruction of Entomoneis are scattered across several studies (Ruck and Theriot 2011, Sorhannus and Fox 2012, Ruck et al 2016, Dabek et al 2017, are frequently without reliable specieslevel identification (Lundholm et al 2002, Witkowski et al 2016, and have not been analyzed together. A better understanding of the taxonomy, diversity, and ecology of this genus would benefit from a synthesis of the available morphological and phylogenetic data.…”