Abstract
This study describes the diatom species Planothidium iberense sp. nov. from a salinity gradient of the Ebro River Estuary in northeastern Spain. A detailed description is given based on light and scanning electron microscopy observations, and the diatom species is compared with morphologically similar Planothidium species. Planothidium iberense is distinguished from P. linkei mainly by its morphometric characteristics, but also by the presence of multiseriate striae, in contrast to biseriate striae in P. linkei. Planothidium iberense is also distinguished from P. delicatulum and P. septentrionale by the presence of an one-side expanded central area on the sternum valve, which is absent in the latter two Planothidium species.
Acknowledgements
This research was supported by funds from the Catalan Government (Generalitat de Catalunya, Agència Catalana de l'Aigua) and Polish Ministry of Science and Higher Education (N N306468538) funds. The authors are very grateful to H. Lange-Bertalot for improving the Latin description, to Slawek Dobosz for LM images, to P. Sharpe for the English revision. We are grateful to two anonymous reviewers, whose constructive comments helped us to improve this manuscript.