Morphology of Amphora lunulata A.H. Wachnicka & E.E. Gaiser and its transfer to Seminavis D.G. Mann

Abstract

An amphoroid diatom epiphytic on seagrass leaves from Hainan Province, southern China was identified as Amphora lunulata Wachnicka & Gaiser. It is characterized by a semi-elliptical valve with acute apices, ventral striae interrupted at the centre, and an axial area, which is well developed on the dorsal side but narrower at the centre, in accordance with its original description. However, as seen under the scanning electronic microscope, A. lunulata presents a combination of features that is consistent with the description of the genus Seminavis, i.e., slit-like areolae covered by hymenes, terminal fissures hooked toward the dorsal side and unornamented valvocopula. Therefore, we redefined the taxonomic status of Amphora lunulata A.H. Wachnicka & E.E. Gaiser and transferred it to the genus Seminavis. We compared the morphometric characteristics of Seminavis lunulata to those of the original description from Wachnicka & Gaiser (2007) and other taxa in Seminavis, including Seminavis atlantica M. Garcia, Seminavis eulensteinii (Grunow) D.B. Danielidis, K. Ford & D. Kennett, Seminavis heidenii D.G. Mann in D.B. Danielidis & D.G. Mann.

Keywords:

• Amphora lunulata
• brackish water
• diatom
• Seminavis
• taxonomy

Acknowledgements

This study was supported by The Natural Science Foundation of China under contract Nos: 41776124, 42076114, 41876146, The National Key Research and Development Program of China under contract No: 2016YFA0601302, Open Research of the Fujian Key Laboratory of Special Marine Bioresources Sustainable Utilization (Fujian Normal University) and Special project of Collaborative Innovation Center for marine biological application technology of Fujian Provincial Department of Education (XTZX-HYSW-1803). We thank Caiming Wu and Luming Yao from the Electron Microscopy Laboratory, Xiamen University, for their assistance with the SEM observation, and American Journal Experts for language editing.

Disclosure statement

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

Additional information

Funding

This work was supported by National Natural Science Foundation of China; The National Key Research and Development Program of China.