Fottea, 2024 (vol. 24), issue 1
Molecular phylogenetics coupled with morphological analyses of Arctic and Antarctic strains place Chamaepinnularia (Bacillariophyta) within the Sellaphoraceae
Katherina Schimani, Nélida Abarca, Jonas Zimmermann, Oliver Skibbe, Regine Jahn, Wolf-Henning Kusber, Thomas Leya, Demetrio Mora
Fottea 2024, 24(1):1-22 | DOI: 10.5507/fot.2023.002 
The diatom genus Chamaepinnularia was first published by Lange-Bertalot et Krammer in 1996 to accommodate several small species previously included within Navicula and Pinnularia. Despite its morphological similarity to those two genera, the family-level classification of Chamaepinnularia has been considered incertae sedis since its description almost three decades ago. We provide the first molecular characterisation (18S and rbcL) of the genus based on cultured polar strains and investigated its phylogenetic placement. Molecular data are complemented with observations on living cells, as well as detailed examination...
The CIMS (Cyanobacterial ITS motif slicer) for molecular systematics
Nicolas A. Labrada, Callahan A. McGovern, Aimee L. Thomas, Anne C. Hurley, Marie R. Mooney, Dale A. Casamatta
Fottea 2024, 24(1):23-26 | DOI: 10.5507/fot.2023.008
The 16S-23S rRNA Internal Transcribed Spacer (ITS) is a commonly employed taxonomic marker in cyanobacterial systematics. Due to numerous challenges in articulating phylogenetic relationships within this ubiquitous, ancient lineage, a polyphasic approach including 16S rRNA sequence data, ecology, morphology, and ITS secondary structure analysis has become the standard. In particular, the ITS motifs are being utilized in the erection of novel and cryptic taxa. However, this is challenging as researchers must manually mine and parse sequence data to visually find and identify ITS structures. This painstaking process deters researchers from using ITS...
Maricoleus vaginatus gen. et sp. nov. (Oculatellaceae, Synechococcales), a novel cyanobacterium isolated from a marine ecosystem in China
Ruozhen Geng, Yao Cheng, Shanjia Chen, He Zhang, Peng Xiao, Si Chen, Zenglin Ma, Bingnan Han, Renhui Li
Fottea 2024, 24(1):27-41 | DOI: 10.5507/fot.2023.005
Cyanobacteria are widely distributed prokaryotes that play important roles as primary producers in diverse ecosystems. However, taxonomic studies focusing on cyanobacteria from marine ecosystems are rarer than those dealing with cyanobacteria from freshwater environments. In this study, a strain of Leptolyngbya-like filaments was isolated from colonies attached to the aquatic weed Acorus calamus in Xincun Port, Hainan Province, China. The strain (named WZU 0102) was examined using the polyphasic approach, i.e. the combination of morphology, ultrastructure, phylogeny of 16S rRNA gene and ITS secondary structures. Although this newly isolated...
Hidden complexity: An assessment of species diversity within the genus Discostella (Bacillariophyta)
Konrad Schultz, Mirko Dreßler, Olivier Jacques, Armin Springer, Marcus Frank, Thomas Hübener
Fottea 2024, 24(1):42-60 | DOI: 10.5507/fot.2023.010
The centric diatom genus Discostella is common in freshwater communities worldwide. Sixteen extant species are currently known, many of which are morphologically very similar. In applied taxonomy mostly broader concepts of D. stelligera and D. pseudostelligera are used. To assess the species diversity of the genus, 58 strains were cultivated and investigated using morphometric and molecular methods, obtaining the first multi-gene phylogeny of Discostella. Up to 22 operational taxonomic units were identified. For the taxonomic assignment of the OTUs a detailed morphological analysis including several type materials was performed....
Three new Simonsenia species (Bacillariophyta) from Brazil
Eduardo Antonio Tusset, Priscila Izabel Tremarin, Maria Gabrielle Rodrigues Maciel, Kaoli Pereira Cavalcante, Thelma A.V. Ludwig, Luciana de Souza Cardoso
Fottea 2024, 24(1):61-72 | DOI: 10.5507/fot.2023.009
The genus Simonsenia is characterized by the raphe system that opens into a longitudinal channel over a marginal keel, and small circular areolae, occluded by hymens. So far, the occurrence of Simonsenia species in Brazil is known only by two records of S. delognei, documented in light microscopy. Here, are described three new species of Simonsenia, one from karst freshwater environments and two from an estuarine stream. Also, we report S. delicatula for the first time to Brazil, in a lotic freshwater body. The new species are distinguished from each other and from similar Simonsenia taxa mainly due to size,...
Ectorea stella gen. et sp. nov. (Bacillariophyta), a cruciform diatom from Quaternary deposits of South America and emended description for E. inflatissima comb. nov.
Gisele C. Marquardt, Denise C. Bicudo, Carlos E. de M. Bicudo, Marie-Pierre Ledru, Carlos E. Wetzel
Fottea 2024, 24(1):73-84 | DOI: 10.5507/fot.2023.011
Ectorea stella Marquardt et C.E.Wetzel, gen. et sp. nov., a cruciform 'araphid' diatom is proposed from Quaternary deposits of the Colônia basin, Southeast Brazil, based on light and scanning electron microscopy observations. Type material of the morphologically most similar species Fragilaria inflatissima Hustedt was also examined and a new combination for the taxon is proposed as well. The new genus diagnostic features include valves strongly inflated transapically, presence of a wide hyaline sternum bordered by spines, inconspicuous striae composed of rounded areolae without volae or rotae and restricted to mantle or to the marginal...
Taxonomic and ecological characterization of three symmetric biraphid diatom species from streams in Cyprus
Marco Cantonati, Nicola Angeli, Olena Bilous, Ionel Ciugulea, Horst Lange-Bertalot, Athina Papatheodoulou, Abdullah A. Saber
Fottea 2024, 24(1):85-98 | DOI: 10.5507/fot.2023.012
Environmental factors and diatoms were studied in 151 stations in Cypriot streams. Since Navicula simplex Krasske [new combination: Craticula simplex (Krasske) Levkov] is based on the small-scale drawing of a single valve and the type material is no longer available, we provide additional ecological, morphological, and ultrastructural data, and an epitype for C. simplex, which is distinguished by valve outline and stria density, and occurs in small, nutrient-enriched streams. Two other symmetric biraphid species are proposed as new to science based on light and scanning electron microscopy, careful comparison with similar established...
Description of Azorothrix ramosa gen. et sp. nov. (Tolypotrichaceae, Cyanobacteria), a new Tolypotrichaceae from Atlantic oceanic islands
Rúben Luz, Guilherme S. Hentschke, Rita Cordeiro, Amélia Fonseca, Ralph Urbatzka, Vítor Vasconcelos, Vítor Gonçalves
Fottea 2024, 24(1):99-108 | DOI: 10.5507/fot.2023.014
The Tolypotrichaceae is a well-defined family within the filamentous heterocyst-forming cyanobacteria. However, the morphological and genetic similarity of some of its genera is very high, making the taxonomic assessment and the description of new taxa in this family challenging. Here we describe six strains of Tolypothrix-like cyanobacteria that were isolated from freshwater lakes and streams from São Miguel Island (Azores Archipelago, Portugal), and deposited in the BACA collection. All strains showed morphological similarities, restricting them to the same taxa, with the phylogenetic analysis revealing a distinct position in the Tolypotrichaceae...
A new terrestrial species of Diplosphaera (Trebouxiophyceae), Diplosphaera sundellii, from a sodic-saline slick in Warren Prairie Natural Area, Arkansas, USA
Kengor N. Thermozier, Marvin W. Fawley, Karen P. Fawley
Fottea 2024, 24(1):109-117 | DOI: 10.5507/fot.2023.013
Diplosphaera Bialosuknia emend Vischer (Chlorophyta; Trebouxiophyceae) is a very small green alga commonly found as a photobiont in lichens and free-living in soil. Cells of Diplosphaera are spherical or nearly so and often grouped in short chains. There is essentially no morphological variation among the strains of the single recognized species of this genus, D. chodatii. In our study of the soil algal communities of Warren Prairie Natural Area in southeast Arkansas, USA, we isolated several strains that matched the morphological characteristics of the genus Diplosphaera from the biotic crust of a sodic-saline slick. Phylogenetic...
Actinella guianensis Grunow (Eunotiaceae): analysis of the type material and the description of Actinella cordiformis sp. nov.
Angela Maria da Silva-Lehmkuhl, João Marcos Souza Coêlho, John P. Kociolek, Elton Augusto Lehmkuhl, Bart Van de Vijver, Tanja Schuster, Thelma A. V. Ludwig
Fottea 2024, 24(1):118-135 | DOI: 10.5507/fot.2023.015
The taxonomic concept of Actinella guianensis Grunow is well-established in the literature. However, during the analysis of recent samples from two Amazon blackwater habitats, we found an uncommon and oddly shaped Actinella taxon, which corresponds to what is reported in Grunow's drawings in Van Heurck's Atlas as the type species of A. guianensis. To understand the identity of the uncommonly shaped Actinella, we revisited the type materials and the literature citing A. guianensis and compared them with the population found in samples recently collected. Two distinct morphologies were found in the original material....