Four Achnanthidium species (Bacillariophyta) formerly identified as Achnanthidium minutissimum from the Antarctic Region

Abstract

Abstract. Four taxa belonging to the complex of species around Achnanthidium minutissimum were found during the ongoing taxonomic revision of the Antarctic freshwater and limno-terrestrial diatom flora. Two taxa were previously described as Achnanthidium lailae and A. sieminskae. Two others were formerly identified as A. minutissimum but detailed light and scanning electron microscopical observations revealed sufficient morphological differences compared to the type of A. minutissimum, to justify their separation and description as new taxa: Achnanthidium indistinctum and A. maritimo-antarcticum. The morphology and ecology of all four taxa are discussed comparing the species with morphologically similar taxa. The biogeographical consequences of the splitting of the former A. minutissimum complex in the Antarctic Region are discussed.

Diatom communities in thermo-mineral springs of Galicia (NW Spain)

“…Its widespread occurrence throughout Europe contributes to the generally accepted idea that it is a ubiquitous taxon (Ector 2011). However, a complexity of forms has been attributed to this species and new taxa described from its varieties (Potapova & Hamilton 2007, Van de Vijver & Kopalová 2014. Nevertheless, moderate abundance of A. minutissimum in a river (0-25%) has been considered as an indicator of no disturbance (Stevenson & Bahls 1999).…”

Periphytic diatoms (Bacillariophyta) of water bodies of the National Nature Park «Pyriatynsky»

“…Ідентифікацію діатомових водоростей проводили за визначниками серії «Süßwasserflora von Mitteleuropa» [KRAMMER, LANGE-BERTALOT, 1986, 1989, 1991, 1991, «Diatoms of Europe» [KRAMMER, 2000[KRAMMER, , 2002[KRAMMER, , 2003LANGE-BERTALOT et al, 2011;LANGE-BERTALOT, 2001;LEVKOV, 2009;LEVKOV et al, 2013], Bibliotheca diatomologica [KRAMMER, 1997], Iconographia Diatomologia [REINCHARDT, 1999], «Diatomeen im Süßwasser-Benthos von Mitteleuropa» , матеріалами таксономічних зібрань та шкіл [VAN DE VIJVER et al, 2010;VAN DE VIJVER, MERTENS, 2011, 2012VAN DE VIJVER, 2013, 2014, 2015, за монографіями та статтями, щодо окремих таксонів діатомей [JAHN et al, 2009;LANGE-et al, 2014;WETZEL et al, 2015;KULIKOVSKIY et al, 2015] та електронними базами даних [DIATOMS…, 2016]. …”

A Study of the Morphology and Distribution of four Achnanthidium Kütz. Species (Bacillariophyta), Implications for Ecological Status Assessment, and Description of two New European Species

“…Over 35 new taxa have been described in the last ten years alone from aquatic and subaerial habitats including several species with straight terminal raphe fissures (e.g. Taylor et al 2011; Van de Vijver et al 2011a;Van de Vijver & Kopalová 2014;Pinseel et al 2017;Krahn et al 2018;You et al 2019;Miao et al 2020). Despite this progress in understanding species diversity in Achnanthidium, there are still considerable problems with the identification of taxa, in particular of the small capitate species, including in well studied regions such as Europe (Gottschalk & Kahlert 2012 and references therein;Wetzel et al 2019;Kennedy & Buckley 2021).…”