Fottea, 2024 (vol. 24), issue 2
Original article
Revision of the pantropical genus Brasilonema (Nostocales, Cyanobacteria), with the description of 24 species new to science
Markéta Bohunická, Jeffrey R. Johansen, Chelsea D. Villanueva, Jan Mareš, Lenka Štenclová, Itzel Becerra-Absalón, Tomáš Hauer, Jan Kaštovský
Fottea 2024, 24(2):137-184 | DOI: 10.5507/fot.2024.002 
Brasilonema was separated from Scytonema only in 2007 (Fiore et al. 2007). It possesses diagnostic morphological characteristics such as vacuole-like structures in older cells, frequent purple pigmentation of cells, rare false branching and fasciculate growth of filaments. Prior to this study, Brasilonema was always found attached to the substrate in subaerophytic habitats, exclusively in tropical-subtropical biomes (Brazil, Guadeloupe, Hawaii, Mexico). We have gathered 76 new Brasilonema strains from North, Central and South America, central Africa, South and East Asia and Europe, including specialized subaerophytic habitats...
A comprehensive study of Macrochaete oelandica sp. nov., the second known cyanobiont of lichen Placynthium nigrum in Europe
Alica Košuthová, Petr Dvořák, Mats Wedin, Alica Hindáková
Fottea 2024, 24(2):185-197 | DOI: 10.5507/fot.2024.003
Cyanobacteria, a diverse group of photosynthetic bacteria, act as primary symbionts for carbohydrate production in about 10% of lichenized fungi, referred to as cyanolichens. This study investigates the effect of different living conditions on the morphology of one cyanobacterium, comparing the cyanobacterium in the lichen symbiosis with the same species in culture. The lichen Placynthium nigrum served as a suitable model. We examined the cyanobacterial 16S rRNA, fungal mtSSU rDNA, and MCM7 sequences using ML analyses, along with analysis of 16S-23S ITS sequences to explore DNA helix structures. Based on the results, we propose here a new cyanobacterial...
The genus Humidophila (Bacillariophyta) in Greenland with the description of 2 new species
Charlotte Goeyers, Koen Sabbe, Elie Verleyen, Paul B. Hamilton, Tyler J. Kohler, Bart Van de Vijver
Fottea 2024, 24(2):198-221 | DOI: 10.5507/fot.2024.004
During a survey of the terrestrial moss diatom flora in Greenland, two unknown Humidophila species were observed that could not be identified using the currently available literature. Detailed morphological analysis using both light and scanning electron microscopy revealed sufficient morphological differentiation from known species to describe these as new species: H. helderiana sp. nov and H. mitosis sp. nov. Formal descriptions are presented, each illustrated by light and scanning electron micrographs, and the new species are compared with similar Humidophila taxa worldwide. Additionally, eight previously described species...
Taxonomic transfer of Gongrosira burmanica Skuja (Chaetophorales, Chlorophyceae) to Ulvella P. Crouan et H. Crouan (Ulvales, Ulvophyceae) based on morphological observation and phylogenetic analyses
Benwen Liu, Qingyu Dai, Yukang Liu, Huan Zhu, Guoxiang Liu
Fottea 2024, 24(2):222-231 | DOI: 10.5507/fot.2023.016
: Two green algal specimens, newly recorded from China, were identified as Gongrosira burmanica Skuja based on their distinctive morphology. The thallus of these specimens appeared hemispherical, forming cushion-like masses with calcification, and featured erect filaments that were pseudodichotomously branched and partially merged with each other, radiating from the base. Ultrastructural investigation, particularly the observation of pyrenoids penetrated by thylakoid membranes and the absence of plasmodesmata in adjacent cells, provided confirmation that Gongrosira burmanica Skuja should be excluded from the order Chaetophorales....
Limnothece alkaliphila gen. et sp. nov. (Chroococcales, Cyanobacteria) from an alkaline lake in Mongolia Plateau, China
Qi Zhang, Lin Li, Zihan Yang, Tianli Li, Lingling Zheng, Lirong Song
Fottea 2024, 24(2):232-243 | DOI: 10.5507/fot.2023.017
A coccoid cyanobacterial strain FACHB-3576 was isolated from Lake Hamatai, an alkaline-saline lake located near the Ordos Spirulina Industrial Park, Ordos, Inner Mongolia, China. This strain exhibited morphological similarities to the genus Cyanobacterium. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain FACHB-3576 formed a unique clade, distinctly separate from the other genera within the family Geminocystaceae. The genetic identity of 16S rRNA sequence between our strain and all other currently described genera in Geminocystaceae, including Cyanobacterium, was less than 95%. Moreover, this strain was...
A first approach to the study of epizoic diatoms on marine benthic macroinvertebrates in Atlantic Patagonian waters (San Jorge Gulf) with SEM description of the most abundant taxa: Cocconeis patagonica sp. nov., Pseudogomphonema kamtschaticum and Tabularia investiens
Adrián O. Cefarelli, Catherine Riaux-Gobin, Martín A. Varisco, Martha E. Ferrario, Cecilia Castaños, Nelson D. Bovcon, David M. Williams
Fottea 2024, 24(2):244-260 | DOI: 10.5507/fot.2024.001
Numerous organisms play a host role for a variety of marine and freshwater diatoms and many have yet to be studied in detail. In particular, along the Argentine coast, there have been very few studies on epizoic diatoms. Through the analysis of ascidians, decapods, echinoderms and gastropods sampled from Atlantic Patagonian waters (San Jorge Gulf), this is the first study in the region on epizoic diatoms found on benthic macroinvertebrates. Thirty-one potential host samples, including 14 macroinvertebrates taxa, were examined from different stations. The epizoic diatom taxa found at the highest relative abundance, namely Cocconeis patagonica...
Mallomonas gigantica sp. nov., an Eocene synurophyte possessing the largest known siliceous scales
Peter A. Siver
Fottea 2024, 24(2):261-268 | DOI: 10.5507/fot.2024.006
A new fossil species representing the genus Mallomonas, M. gigantica, is described from the Giraffe Pipe Eocene maar lake locality situated near the Arctic Circle in northern Canada. The new species possesses rolled bristles and two basic types of scales that lack V-ribs, body scales and specialized apical scales. Mallomonas gigantica possesses the largest body scales reported for the genus, including for both fossil and contemporary taxa. Scales reached 12 µm in length and with a surface area near 100 µm2. Body scales are large, square-shaped, with a narrow posterior rim, large and thick anterior...