Fottea, 2025 (vol. 25), issue 2
Original article
Revisiting Chrysococcus (Chrysophyceae): new phylogenetic evidence and evolutionary implications
Veronica Malavasi, Martin Pusztai, Katarzyna Jankowska, Bo¿ena Zakry¶, Pavel ©kaloud
Fottea 2025, 25(2):121-127 | DOI: 10.5507/fot.2025.001 
Loricate golden algae (Chrysophyceae) are photosynthetic microorganisms characterized by a lorica, a rigid or semi-rigid protective casing made of organic material, sometimes reinforced with silica or iron. The lorica's diverse shapes and intricate ornamentation serve as both adaptive strategies and taxonomic markers. Here, we identified, for the first time, the molecular phylogenetic position of a loricate genus Chrysococcus, based on genetic investigations of two freshwater populations in Poland. The genus was resolved to form a well-supported clade with Chrysosaccus within the order Chrysosaccales. Accordingly, this order represents...
Frustulia lineata and Frustulia magnifica, two new species of diatom from south Brazil
Paula Carolina Ferreira, Vanessa Merlo Kava, Rodrigo Aluisio, Thelma Alvim Veiga Ludwig
Fottea 2025, 25(2):128-135 | DOI: 10.5507/fot.2025.002
During studies on the diversity of Frustulia in the state of Paraná, Brazil, two different morphological populations did not correspond exactly to any known described species. This paper describes these species as Frustulia lineata sp. nov. and Frustulia magnifica sp. nov. The samples were collected in lotic environments inserted in the south Brazil Atlantic Forest region. Frustulia lineata sp. nov. is mainly characterized by linear-lanceolate valves with small dimensions, sharing morphological similarities with Frustulia marginata Amossé and Frustulia saxonica f. indica Sarode et Kamat. Frustulia...
Neoluticola (Bacillariophyceae) a new genus of colonial diatoms from tropical America
Julian Simonato, Silvia E. Sala, John P. Kociolek
Fottea 2025, 25(2):136-149 | DOI: 10.5507/fot.2025.006
In the framework of a study of the genus Luticola Mann we collected and processed samples from different ecoregions of Argentina, analyzed them with light microscopy (LM) and scanning electron microscopy (SEM). In aerophilous samples collected in Misiones Province, Argentina, we found colonial specimens. The aim of this work is to elucidate the identity of the colonial forms found in aerophilous samples in NE Argentina. In the present study, we describe the genus Neoluticola Simonato, Sala et Kociolek and four species: Neoluticola spinosa Simonato, Sala et Kociolek sp. nov., Neoluticola arrechensis Simonato, Sala et Kociolek...
Streptosarcina costaricana var. goloustica var. nov. (Klebsormidiophyceae, Charophyta) from soils of Baikal mountains, Russia
Irina N. Egorova, Nina V. Kulakova, Olga N. Boldina
Fottea 2025, 25(2):150-168 | DOI: 10.5507/fot.2025.004
The charophyte algae of the genus Streptosarcina (Hormidiellales) are quite rare terrestrial protists, according to current knowledge. The genus consists of two species, S. arenaria and S. costaricana, which are isolated in Eastern Europe and Central America, respectively. Only five strains of the genus have been studied using microscopy and/or molecular methods, based on published data. Here, we examined two strains, IRK-A 417 and 448, isolated from the chestnut soils of the Primorsky Range at the southwestern shore of Lake Baikal. The combination of molecular (18S rDNA, ITS, rbcL) and microscopy data (LM and TEM) was used to...
Mallomonas intermedia: A case study of speciation and evolutionary dynamics of protists
Pavel ©kaloud, Magda ©kaloudová, Petr Knotek, Iva Jadrná, Martin Pusztai
Fottea 2025, 25(2):169-182 | DOI: 10.5507/fot.2025.008
A total of 81 strains morphologically corresponding to the circumscription of Mallomonas intermedia were isolated from 27 freshwater localities across Europe and North America. Molecular genetic analyses revealed two distinct lineages with a strict geographical pattern, which diverged approximately 8 million years ago. According to comparative morphological analyses, we concluded that European populations corresponded to M. intermedia, whereas North American populations were described as a new species, M. retimedia sp. nov. The most notable morphological difference between the species is in the number of pores enclosed in the mesh...
Flavoaurantia, a new genus of the Chlorobotryaceae (Eustigmatales, Eustigmatophyceae) with the single species, Flavoaurantia irregularis
Christie L. Alexandre, Yvonne Nìmcová, Marvin W. Fawley, Karen P. Fawley
Fottea 2025, 25(2):183-190 | DOI: 10.5507/fot.2025.003
An algal strain with the morphological characteristics of the Eustigmatophyceae was isolated from a small pond in Itasca State Park, Minnesota, USA. Phylogenetic analyses of the DNA sequences from the nuclear 18S rDNA and the plastid rbcL loci both placed the strain in the order Eustigmatales and family Chlorobotryaceae. The new strain was not clearly allied with any lineage within the Chlorobotryaceae. Morphological features as determined by both light microscopy and transmission electron microscopy were typical for the Eustigmatales, except for the presence of an irregular surface of the cell wall (including the presence of stipitate or digitate...
Sellaphora temporalis sp. nov., Sellaphora catalonica sp. nov., and Nitzschia curvirecta sp. nov.: Three new diatoms (Bacillariophyta) from disconnected pools in the Iberian Peninsula
Guillermo Quevedo-Ortiz, Joan Gomà, Saul Blanco
Fottea 2025, 25(2):191-202 | DOI: 10.5507/fot.2025.005
Disconnected pools are temporary habitats of great ecological importance that can maintain high aquatic biodiversity. However, little is known about the composition and distribution of algal communities in the Mediterranean basin. During a diatom flora study conducted on the Iberian Peninsula, several populations of unknown taxa were found. Detailed observations with optical and scanning electron microscopes allowed for the description of three new taxa to science: Sellaphora temporalis sp. nov., Sellaphora catalonica sp. nov., and Nitzschia curvirecta sp. nov. Differential diagnostic criteria with respect to similar taxa are briefly...
Widespread and homologous life-history traits within the Rhopalodiales (Bacillariophyceae)
Heidi Abresch, Mark B. Edlund, Scott R. Miller
Fottea 2025, 25(2):203-211 | DOI: 10.5507/fot.2025.007
Significant changes have been proposed for the order Rhopalodiales, including subsuming Rhopalodia O.Müll. into Epithemia Kütz. to maintain monophyly and recognition of the genus Tetralunata Hamsher et al. However, hesitancies about adopting these higher-level classifications remain. We report widespread and homologous internal valve and life history traits as evidence to guide higher-level classification within the Rhopalodiales. We provide the first reports of internal valve formations in five species and show examples from six species representing multiple branches in the Rhopalodiales: Epithemia (Rhopalodia) gibba (Ehrenb.)...
The names of phyla and classes of blue-green algae (cyanobacteria, cyanophytes) and a typified name: Cyanobacteriophyta Oren, Mare¹ et Rippka
Boris Aleksovski, Svetislav Krstiæ, Michael D. Guiry
Fottea 2025, 25(2):212-217 | DOI: 10.5507/fot.2025.009
The naming of organisms long known as "blue-green algae" or "cyanophytes", and more recently as "cyanobacteria", is currently governed by both the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN) and the International Code of Nomenclature of Prokaryotes (ICNP) and a reciprocal principle of code coordination has been agreed so that names validated in either code are treated as valid in the other code. Under the ICN, both descriptive and typified names above the level of family are permitted, and the principle of priority does not apply but there is a recommendation that priority be applied to typified names. The current...
Personalia
It is with great sadness we note that Doc. RNDr. Tomá¹ Kalina, CSc., passed away on June 28th, 2025 at the age of nearly 90
Czech Phycological Society
Fottea 2025, 25(2)
The first and long-time chairman of the Czech Phycological Society, which he founded in 2003 after its separation from the Czech Botanical Society, he worked throughout his life at the Department of Botany of the Faculty of Science, Charles University in Prague. During his career, he published more than 90 papers, mainly focused on the taxonomy and cytology of green algae and chrysomonads. The genus Kalinella, which belongs to the chlorelloid representatives in the class Trebouxiophyceae, and the freshwater chrysomonad flagellate Mallomonas kalinae have been named in his honor.