One new species of Achnanthidium Kützing (Bacillariophyta, Achnanthidiaceae) from the upper Han River, China

Abstract

The upper Han River plays an important role in the Middle Route of the North to South Water Transfer Project in China. During an investigation of diatom biodiversity in this area, a new benthic monoraphid diatom, Achnanthidium ampliatum sp. nov. was observed from an alkaline tributary. This new species has relatively large valves, with a lanceolate axial area and distal raphe ends curved to the same side on the raphe valve, linear axial area in rapheless valves, with uniseriate striae and round to short slit-like areolae on both valves. We present light and scanning electron microscopic observations to document the new species. A. ampliatum sp. nov. is easily separated from other, similar Achnanthidium and Psammothidum taxa, and we provide comparisons with species that have similar outlines and valve features.

Two new freshwater species of the genus Achnanthidium (Bacillariophyta, Achnanthidiaceae) from Qingxi River, China

“…Presently, the number of species in the genus Achnanthidium is greater than 200 (Marquardt et al 2017;Kociolek et al 2018;You et al 2021). Before the year of 2000, 11 new Achnanthes species had been described from China (Hustedt 1922;Jao 1964;Jao et al 1974;Qi and Xie 1984;Chen 1994, 1996;Liu et al 2021). Some of these species should be transferred to Achnanthidium, but owing to the loss of the type material, it is difficult to confirm their taxonomic position.…”

“…Some of these species should be transferred to Achnanthidium, but owing to the loss of the type material, it is difficult to confirm their taxonomic position. It is, therefore, necessary to collect samples from the type locality, and re-evaluate their taxonomic position (Liu et al 2021). From 2001 to 2021, 14 new Achnanthidium species have been described from China (Liu et al 2016;Yu et al 2018, 2019a, b, You et al 2019Liu et al 2021).…”

“…It is, therefore, necessary to collect samples from the type locality, and re-evaluate their taxonomic position (Liu et al 2021). From 2001 to 2021, 14 new Achnanthidium species have been described from China (Liu et al 2016;Yu et al 2018, 2019a, b, You et al 2019Liu et al 2021). During an investigation of the freshwater diatoms from the Qingxi River, two unknown Achnanthidium species were discovered.…”

Achnanthidium gladius sp. nov. (Bacillariophyceae) – a new monoraphid diatom species from Indonesia

“…Since the beginning of the 21 st century many descriptions of new Achnanthidium species have been published (Monnier et al 2004;Cantonati and Lange-Bertalot 2006;Ivanov and Ector 2006;Potapova 2006;Wojtal et al 2010;Liu et al 2021). Furthermore, the type materials of earlier described species are studied using light microscopy (LM) and scanning electron microscopy (SEM) (Hlúbiková et al 2011;Van de Vijver et al 2011).…”