Multigene phylogenetic data place monoraphid diatoms Schizostauron and Astartiella along with other fistula-bearing genera in the Stauroneidaceae1

New genera and new species of Catenulaceae (Bacillariophyta) from Coral Reef habitat of two Indonesia islands-Bawean and Sulawesi-A morphological approach

Indonesia is listed as a region with high marine biodiversity, especially when considering the three large tropical ecosystems: seagrass beds, mangroves and coral reefs. It is likely that the biodiversity of diatoms in this area is also high. Samples for this research were taken from the remote area of Bawean Island and Tomini Gulf in Central Sulawesi. In this research, we explored marine benthic diatoms from coral reef areas and presented two new genera: Paracatenula and Wallaceago, and seven new species: Paracatenulaporostriata sp. nov., Wallaceagoporostriatus sp. nov., Catenulaboyanensis sp. nov., C.komodensis sp. nov., C.decusa sp. nov., C.densestriata sp. nov., and Catenulopsisbaweana sp. nov. The new genus Paracatenula is characterized by its perforated cingulum, and the genus Wallaceago is distinguished by its proximal and apical raphe ends bent to the ventral side and the presence of a stauros in the mantle.

Description of Naviculavanseea sp. nov. (Naviculales, Naviculaceae), a new species of diatom from the highly alkaline Lake Van (Republic of Türkiye) with complete characterisation of its organellar genomes and multigene phylogeny

The current article describes Naviculavanseeasp. nov., a new species of diatom from Lake Van, a highly alkaline lake in Eastern Anatolia (Türkiye). The description is based on light and scanning electron microscopy performed on two monoclonal cultures. The complete nuclear rRNA clusters and plastid genomes have been sequenced for these two strains and the complete mitogenome for one of them. The plastome of both strains shows the probable loss of a functional ycf35 gene. They also exhibit two IB4 group I introns in their rrl, each encoding for a putative LAGLIDADG homing endonuclease, with the first L1917 IB4 intron reported amongst diatoms. The Maximum Likelihood phylogeny inferred from a concatenated alignment of 18S, rbcL and psbC distinguishes N.vanseea sp. nov. from the morphologically similar species Naviculacincta and Naviculamicrodigitoradiata.

Mitochondrial and Plastid Genomes of the Monoraphid Diatom Schizostauron trachyderma

We provide for the first time the complete plastid and mitochondrial genomes of a monoraphid diatom: Schizostauron trachyderma. The mitogenome is 41,957 bp in size and displays two group II introns in the cox1 gene. The 187,029 bp plastid genome features the typical quadripartite architecture of diatom genomes. It contains a group II intron in the petB gene that overlaps the large single-copy and the inverted repeat region. There is also a group IB4 intron encoding a putative LAGLIDADG homing endonuclease in the rnl gene. The multigene phylogenies conducted provide more evidence of the proximity between S. trachyderma and fistula-bearing species of biraphid diatoms.