Diversity of the genus Orthoseira Thwaites (Bacillariophyceae) from Southeast Asia and Rapa Nui Island with descriptions of four new taxa

Abstract

The genus Orthoseira Thwaites contains centric diatoms typically inhabiting marginal-aquatic or terrestrial habitats. The high morphological plasticity of representatives of the genus and their occurrence in rarely studied terrestrial habitats complicates an overall assessment of their biodiversity and the distribution of particular species. This study presents a description of four new species of this genus from Southeast Asia and Easter Island. They include: O. radiata M.Rybak, Glushchenko & Kulikovskiy sp. nov., O. distincteareolata M.Rybak, Glushchenko & Kulikovskiy sp. nov., O. cylindrica M.Rybak, Glushchenko & Kulikovskiy sp. nov. and Orthoseira rapanuiensis M.Rybak, Witkowski & Lange-Bertalot sp. nov. Additionally, we attempt to provide a solution to the confused taxonomical history of Liparogyra circularis Ehrenberg and provide the first detailed description of Orthoseira tropica (Krasske) Metzeltin & Lange-Bertalot.

Keywords:

• taxonomy
• centric diatoms
• terrestrial habitats
• SE Asia
• Easter Island

Acknowledgments

The authors are grateful to Professor Georg Zizka for sampling the material from Rapa Nui Island. The authors thank Mr Łukasz Skoczylas for collecting materials for this research and the tardigradologist team from the Jagiellonian University, especially Mr Witold Morek for sharing materials used in this present research.

Disclosure statement

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

Additional information

Funding

The project was funded by the Ministry of Science and Higher Education under the name of ‘Regional Excellence Initiative’ in the years 2019–2022 Project No. 026/RID/2018/19. AW acknowledges the Ministry of Education and Science funding within the statutory funds for Institute of Marine and Environmental Sciences (the diatomology team) at the University of Szczecin. The research for MK and AG was carried out as part of the Ministry of Science and Higher Education of the Russian Federation (theme No. 121041200194-7).