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Physarum andinum by SEM. A, B. Three-layered peridium: outer and inner layers membraneous, middle layer calcareous (A: Lado 20683, B: Lado 20683). C-E. Capillitium (C: Lado 20683, D: Lado 20712, E: Lado 20364). F, G. Details of spore ornamentation (F: Lado 20712, G: Lado 20903-HOLOTYPE). H, I. Spores (H: Lado 20364, I: Lado 20903HOLOTYPE). Bars: A 5 200 mm; B 5 20 mm; C 5 100 mm; D, E 5 50 mm; F, G 5 2.5 mm; H, I 5 5 mm.
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A new nivicolous species of Physarum was discovered during the study of myxomycetes in the Patagonian Andes of South America. It is described herein under the name Physarum andinum. The species is characterized by stalked sporophores or more rarely sessile sporocarps or short plasmodiocarps. The sporocarps are strikingly large, reaching 2.6 mm tall...
Context in source publication
Context 1
... are the large size of the sporocarps, that can reach 3 mm diam when open, the peridium with three layers, with a clearly visible inner layer that is distinctly separate from the two other layers (FIGS. 2B, C, 6B, C), and the strongly calcified capillitium with abundant, white calcareous, polygonal nodes con- nected by short limeless threads (FIG. 3C-E). The new species usually forms stalked sporocarps (FIGS. 2A, D, 6A, B), but occasionally short plasmo- diocarpic fructifications are found (FIG. 2E). We observed that the habit depends on the substrate type. Specimens occurring on twigs, bark or wood (85% of the collections) were sporocarpic, while those from grass culms and plant ...
Citations
... Many Physarales are worldwide distributed in terrestrial ecosystems (Lado & Rojas 2018), even in extreme environments (Ronikier & Lado 2013, Wrigley de Basanta et al. 2015, 2018, Novozhilov et al. 2022b, where they are likely more widespread than currently acknowledged (Fiore-Donno et al. 2016). Their fructifications are often found on rotten wood and other vegetal remnants (Novozhilov et al. 2022a) and, exceptionally, from aquatic environments (Kappel & Anken 1992, Lindley et al. 2007 or on living substrates (Townsend et al. 2005, Zhang et al. 2007, while vegetative phases have been isolated as endo commensals (Dyková et al. 2007). ...
... In addition to homoplasy, polymorphism is also related to some of the mentioned characters. For example, the degree of calcification of the capillitium has been confirmed to be variable (Eliasson & Adamonyte 2009), and certain species can develop different sporophore types depending on the substrate (Ronikier & Lado 2013). Thus, the genus Badhamia is a prime example illustrating how the strong systematic importance placed on both the clustered spores and the badhamioid capillitium resulted in the circumscription of a highly polyphyletic taxon. ...
... This is exactly the case of Ph. brunneolum (Fig. 11e) and, to a lesser extent, of Ph. andinum and Ph. mutabile (Fig. 11f), since the dehiscence of its peridium is irregular, but still leaves a cup in the lower part of the sporotheca (Ronikier & Lado 2013). Besides, this genus also comprises Ph. roseum, a species with peridium that only partially persists after dehiscence as a rudimentary cup. ...
The class Myxomycetes consists of free-living protists characterised by their complex life cycle, which includes both microscopic (amoebae, flagellates and cists) and macroscopic stages (spore-bearing fruiting bodies, sclerotia, and plasmodia). Within it, the order Physarales , with more than 450 recognised species, constitutes the largest group. Although previous studies have shown the polyphyly of some of the traditionally accepted genera, its internal phylogenetic relationships have remained uncertain so far, and together with the lack of data for some key species, it prevented any taxonomic and nomenclatural revisions. We have compiled a substantially expanded dataset in terms of both taxon sampling and molecular data, including most of the genera described to date and four unlinked DNA regions, for which we provide partial sequences: nSSU, EF-1α , α-Tub , and mtSSU, analysed through maximum likelihood and Bayesian methods. Our results confirm that the family Didymiaceae is paraphyletic to the rest of Physarales . Within Didymiaceae s.lat., the recent reinstatement of the genus Polyschismium for most species traditionally ascribed to Lepidoderma , except for the type (Ronikier et al. 2022), is further supported here, as well as the definite inclusion of the genus Mucilago in Didymium and Lepidoderma s.str. ( L. tigrinum ) in Diderma (Prikhodko et al. 2023). Additionally, the genus Diachea is redefined to include some species previously treated in Physaraceae ( Craterium spp. with true columella). Within the monophyletic family Physaraceae , most genera are recovered as polyphyletic, suggesting that they should be no longer accepted as currently defined. However, the lack of resolution of some relationships within Physaraceae prevents us from resuscitating or creating several new genera to mitigate polyphyly. Among the well-defined groups with clear molecular signatures, we propose two taxonomic and nomenclatural changes at generic level: 1) a new genus, Nannengaella , is proposed for a major clade containing Physarum globuliferum and other species with heavily calcified sporophores and, often, a true calcareous columella; 2) Lignydium is resurrected for the clade containing Fuligo muscorum . Additionally, Trichamphora is suggested as the correct name for the clade containing Physarum pezizoideum . The taxonomy and nomenclature of some provisional genera, currently synonymous with Fuligo and Physarum , are disentangled, and we provide a comprehensive and updated nomenclatural conspectus that can be used when better resolved phylogenies are obtained. In total, 22 new combinations are proposed in different genera. A provisional key to the genera of the order is also provided.
... The genus is characterized by the capillitium, a network of hyaline tubules connecting calcareous nodes, lime in peridium, capillitium, and the stalk in the form of amorphous granules, the spores dark in mass (Martin & Alexopoulos 1969). Like other representatives of the Physaraceae, the species of Physarum produce a dark brown to black spore mass, and the spores are usually covered by warts and spines (Ronikier & Lado 2013). ...
A new species of Physarum, identified herein as P. karamanicum, developed on debris branches of Cedrus libani collected from the Sarıveliler district of Karaman province in Turkey and applied a moist chamber technique. P. karamanicum is morphologically similar to P. globuliferum, P. auripigmentum, and P. tenerum but is distinguished by sporotheca, stalk, capillitium, and spore features. The new species is characterized by a greenish-gray, globose sporotheca, light brown at the bottom, the remainder yellowish-cream colored stalk, triangular, convex quadrilateral nodes and pale-yellow capillitium, prominent spiny and groups of blunt warts spores, greenish gray peridium. Description of the new species, photographs (light microscope, stereo microscope, and scanning electron microscope), and a key to the closest morphologically related species of the genus are provided.
... This left 1117 entries. Additional five records came from published papers (Yamamoto 1993;Ing, 2009;Tamayama 2000;Ronikier and Lado 2013;Antonopoulos et al., 2018) mentioning localities of Ph. albescens not provided by GBIF. The last source of data (594 records) constituted the private collections of the authors and the collections of M. Meyer, R. Cainelli and Y. Yajima. ...
... For the Southern Hemisphere we have 35 records from southwestern Australia (Stephenson and Shadwick 2009) and New Zealand (Stephenson et al., 2007). A single is occurrence is known from Argentina (Ronikier and Lado 2013). ...
To identify potentially suitable areas for the mostly alpine ecological guild of nivicolous (snowbank) myxomycetes, the worldwide distribution of a distinct morphospecies, Physarum albescens, was modelled with a correlative spatial approach using the software MaxEnt from 537 unique occurrence points. Three models were developed, first with only the 19 bioclimatic variables plus elevation from the WorldClim database, second with regularization to correct for pseudo-absence, and third with additional categorical environmental layer on snow cover. All three models showed high mean AUC (area under the curve) values (>0.970). Output maps were comparable, with the third model perhaps the most realistic. For this model, snow cover, precipitation of the coldest quarter (of the year), and elevation predicted best the distribution of Ph. albescens. Elevation alone is a good predictor only in some regions, since (i) elevation of the occurrence points decreases with increasing latitude, and (ii) elevation wrongly predicts the species' occurrence in arid mountain ranges. The model showed mountains in humid climates with highest incidence, which confirmed field studies: a long-lasting snow cover fluctuating with comparatively mild summers is the decisive factor. As such, the model can serve as a predictive map where fructifications of nivicolous myxomycetes can be expected. Limitations of the model are discussed: cryptic speciation within a morphospecies, including the evolution of reproductively isolated units which may lead to local adaptation and niche differentiation, and wider ranges for myxamoebal populations.
... 5 ( – 14 . 5 ) mm ( Ronikier and Lado 2013 ) and Trichia alpina ( R . E . ...
A new nivicolous species of Perichaena is described from the Andes in Argentina. The most conspicuous characteristics of Perichaena megaspora are the large spores and their ornamentation in the form of flattened warts. The 16-21 μm diam spores make the new species unique in the genus in which all other species have spores rarely reaching 15 μm diam. Twenty-two collections were found in the field during two consecutive years at 10 localities in Mendoza province Argentina, including one collection isolated from a moist chamber culture of ground litter. The new species was examined under stereomicroscope, light microscope and scanning electron microscope and micrographs of relevant details are included.
A new nivicolous myxomycete is described as a result of a comprehensive study of Didymium nivicola collections from the entire range of its occurrence. Statistical analysis of 12 morphological characters, phylogenetic analyses of nuc 18S rDNA and elongation factor 1-alpha gene (EF1A), and a delimitation method (automatic barcode gap diversity) have been applied to corroborate the identity of the new species. A preliminary morphological analysis of D. nivicola revealed high variability of South American populations where four types of spore ornamentation were noted. However, results of molecular study and statistical analysis of morphological characters did not support recognition of these four forms but the distinction of two morphotypes. Consequently, two species have been recognized: D. nivicola and the newly proposed D. pseudonivicola. The new species can be distinguished from D. nivicola by distinctly larger and mostly plasmodiocarpic sporophores, which are scattered to gregarious, paler spores, and by the paler, more delicate and more elastic capillitium. Spore ornamentation of D. pseudonivicola is uniform and can be described as distinctly spiny (pilate under scanning electron microscope [SEM]), whereas those of D. nivicola is more variable, where spines (pilae under SEM) are delicate, distinct, or conspicuous. Additionally, whereas D. nivicola is a species distributed worldwide, D. pseudonivicola occurs only in the austral Andes of Argentina and Chile.
Soil protists play a crucial role in terrestrial ecosystems and often show immense taxonomic diversity. However, for many groups, distribution patterns remain largely unknown. We investigated range-wide intraspecific diversity of a specialized airborne protist (Didymium nivicola Meyl.) that occupies a narrow ecological niche associated with long-lasting snow cover. We sampled 122 collections covering all areas where the species was recorded worldwide. We obtained 105 and 41 sequences of small ribosomal subunit rDNA (SSU) and elongation factor 1-alpha (EF1A), respectively. While the species is very diverse in the austral Andes, Southern Hemisphere (SH; 17 SSU ribotypes and 12 EF1A genotypes identified), its populations are genetically uniform across three continents of the Northern Hemisphere (NH; single ribotype, single genotype). Our results indicate the austral Andes as a possible diversification centre for D. nivicola where populations seem to reproduce sexually. Two main parts of the range display highly contrasting genetic patterns, thus biogeographical history and dynamics. Current distribution of D. nivicola in the NH is likely a result of a dispersal event from the SH and subsequent long-distance dispersal (LDD) that might be associated with a shift to asexual mode of reproduction.
Nivicolous myxomycetes are a group of amoebozoan protists dependent on long-lasting snow cover worldwide. Recent fine-scale analysis of species diversity from the austral Andes revealed high intraspecific variability of most taxa, suggesting independent evolutionary processes and significant differences in species compositions between the Northern (NH) and Southern (SH) Hemispheres. The present study is the second part of this analysis based on representatives of Trichiales. A total of 173 South American collections were studied based on morphological and molecular data, and 15 taxa have been identified. Two of them, Hemitrichia crassifila and Perichaena patagonica, are proposed as new species confirmed by a phylogeny of Trichiales. However, their affinity to the genera in which they are proposed are not confirmed due to polyphyletic character of all genera of Trichiales. Four species, Dianema subretisporum, Trichia contorta var. karstenii, T. nivicola, and T. sordida, are reported for the first time from the Southern Hemisphere. One species, T. alpina, is new for Argentina. Additionally, we provide the first record of Perichaena megaspora from Chile. Specimen frequency and species diversity of Trichiales found at nivicolous localities in the austral Andes are unexpectedly high, exceeding those of Stemonitidales, the most numerous group in the Northern Hemisphere, where Trichiales play a marginal role. By contrast, Trichiales appear the main component of nivicolous assemblages in the Andes. Results of the present work, together with the earlier analysis of Stemonitidales, indicate that the Andes constitute an exceptionally important evolutionary hot spot for nivicolous myxomycetes characterized by an outstanding species diversity.
The plasmodium of Badhamia alpina thrived at lower temperatures (4 °C), and formed fruiting bodies at 8 °C. The yellow sclerotium and plasmodium were found inside a hollow, dead herbaceous stem under melting snow in Apr, and was cultured in moist chambers at 4 °C. The plasmodium did not form fruiting bodies for 6 wk at 4 °C. Sporulation was observed after the incubation temperatures rose to 8 °C. Sporulation occurred in the morning and cell cleavage at 11 a.m. The order of spore wall formation was observed by TEM for 12 h. The outer spore wall ornamentation was formed first followed by internal wall layers. Round electron transparent object was observed in the capillitium and peridium during the latter part of sporulation.
Biodiversity surveys for myxomycetes (Amoebozoa) were carried out in three consecutive years (2009 to 2011) in the cold arid Patagonian Steppe, Argentina. The surveys, the first to cover such an extensive area in South America, form part of the Myxotropic project funded by the Spanish Government. Specimens were collected in 174 localities in four different provinces (Neuquén, Río Negro, Chubut and Santa Cruz), between 36° and 52° S latitudes. The most common types of substrate investigated were the dominant shrubs and grasses of the Patagonian steppe, and the Nothofagus forests, characteristic of the transition areas, but other plants such as small cacti and cushion plants were also included in the survey. A total of 133 different species and 5 varieties of myxomycetes representing 31 genera were identified in the 1134 specimens collected either in the field, or from moist chamber cultures prepared with samples of plant material obtained from the same collecting sites. The results include one species new to science, Perichaena nigra, and 17 species and two varieties that were previously unknown for either the Neotropics or South America, Badhamia armillata, Dianema mongolicum, Didymium annulisporum, D. leptotrychum, D. orthonemata, D. sturgisii, Echinostelium coelocephalum, Licea deplanata, L. nannengae, Macbrideola argentea, M. oblonga, Oligonema aurantium, Perichaena luteola, P. madagascariensis, Physarum luteolum, Protophysarum phloiogenum, Trichia contorta var. attenuata, T. contorta var. iowensis, T. erecta. An additional 19 species are new records for Argentina. These additions make Argentina the country in South America, at present, with the greatest number of myxomycetes catalogued having more than 50% of the species cited from the whole Neotropics. Diversity and biogeographic distribution of these organisms are discussed, and taxonomic comments on rare or unusual species are included and illustrated with photographs by LM and SEM. The results indicate that the myxomycetes, are widely distributed and are a normal component of Patagonian biota. Many of the substrates investigated were endemic plants from the region and are new substrates for a number of species of myxomycete. Differences between the variety of species in this area and others in Argentina and Chile, suggest a certain regional specialization of these organisms, the assemblage of which appear to depend on plant substrate species.
