A new monoraphid diatom species from the genus Karayevia sensu lato (Bacillariophyceae: Stauroneidaceae) with remarks on taxonomy and phylogeny of the genus

Abstract

A new monoraphid diatom, Karayevia chelonica sp. nov., is described from Nha Trang, Vietnam, isolated from marine littoral habitats. Phylogenetic analysis based on partial 18S rDNA and rbcL sequences places this species within the family Stauroneidaceae, and related to other monoraphid species. Karayevia chelonica sp. nov. differs from other species in the genus in stria density and a broad axial area on the rapheless valve. Morphology and taxonomy of the closely related genera Karayevia, Kolbesia and Madinithidium are discussed. Based on morphological characteristics, we conclude that these three genera might represent a single genus, however, further molecular investigation is required to clarify their taxonomic and systematic affinities.

Keywords:

• diatoms
• Karayevia
• new species
• molecular investigations
• South-East Asia
• Vietnam

Acknowledgements

The authors are grateful to the staff of the Centre of Electron Microscopy of the Papanin’s Institute for Biology of Inland Waters, RAS, for technical assistance. Samples were collected during expeditions organized and permitted by the Joint Russian-Vietnam Tropical Centre, Ecolan 3.2 theme.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Russian Science Foundation No. 19-14-00320 (LM, sample preparation for SEM) and by framework of the state assignment (theme No. 121041200194-7) for finishing the manuscript.