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Research into freshwater fungi has generated a wealth of information over the past decades with various published articles, i.e., reviews, books, and monographs. With the advancement of
methodologies used in freshwater fungal research, and numerous mycologists working on this ecological group, our knowledge progress and understanding of freshwater...
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... and biodiversity studies (Tsui & Hyde 2003). Cai et al. (2006a) reviewed and compiled descriptions of 100 freshwater fungal genera with comprehensive description, photographic plates, and notes. Freshwater Ascomycota Since 1856, the number of novel taxa discovered from freshwater habitats has an increasing trend with no sign of reaching a plateau (Fig. 1). It has the highest number of discoveries in the past decade (2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019), wherein about 433 species have been discovered from 2010-2019 [data 200 extrapolated from Calabon et al. (2022), Figs 2, 3]. Most are Sordariomycetes represented by 489 freshwater species followed by ...
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... we used the ITS, LSU, and β-tubulin (tub2) sequence data available from Eurotiomycetes in freshwater and other environments to construct a phylogenetic tree (Fig. 10). The phylogenetic position and distribution of freshwater Eurotiomycetes species in the main orders and families are summarized. ...
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... we constructed a phylogenetic tree using the available molecular sequences of most of the currently known freshwater Eurotiomycetes species (Fig. 10). Our analysis shows that freshwater Eurotiomycetes are dispersed in three subclasses, Chaetothyriomycetidae, Eurotiomycetidae and Sclerococcomycetidae. The main orders include Chaetothyriales, Eurotiales and Verrucariales, and a small number are distributed in Sclerococcales. Although many species have molecular sequence data, the ...
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... thalli of Harpellales are septate and can be either branched or unbranched. Branches, when present, usually appear at the apical area of elongated thallial cells, just below each septum. Different branching patterns can be observed, sometimes having a relative taxonomic importance (Valle 2004) (Fig. ...
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... anchoring element or holdfast of Harpellales can be cellular (holdfast cell) or, more commonly, an acellular secretion (Lichtwardt 1986) (Fig. 12). A combination of both is possible and, in any case, we find great morphological diversity in the holdfast structure. The thallus may be erect, and then fixed by a basal holdfast, or prostrate, laying on the inner gut membrane. In this case, the thallial cells that contact directly with the gut, often develop secondary pit-like or ...
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... of both is possible and, in any case, we find great morphological diversity in the holdfast structure. The thallus may be erect, and then fixed by a basal holdfast, or prostrate, laying on the inner gut membrane. In this case, the thallial cells that contact directly with the gut, often develop secondary pit-like or peg-like fixation structures (Fig. 12a), or secreted holdfast material, to ensure a secure adhesion to the gut lining (Valle 2004). Several species found attached to the peritrophic matrix in dipteran hosts penetrate the lining and form a "foot-like" holdfast, or they can adhere by a drop of secreted material (Lichtwardt 1986) (Fig. ...
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... pit-like or peg-like fixation structures (Fig. 12a), or secreted holdfast material, to ensure a secure adhesion to the gut lining (Valle 2004). Several species found attached to the peritrophic matrix in dipteran hosts penetrate the lining and form a "foot-like" holdfast, or they can adhere by a drop of secreted material (Lichtwardt 1986) (Fig. ...
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... species are characterized by their asexual undeciduous monosporic sporangiospores, named trichospores. The trichospores originate from generative cells arranged in series on fertile branches ( Lichtwardt et al. 2001a). The number of trichospores and arrangement on a fertile branch can be important in classification (Fig. 13). Trichospores usually have one or more appendages, which facilitate its adhesion to the substrate outside the gut, reducing dispersal by water drift ( Lichtwardt et al. 2001a, Valle 2004). There are no appendages in the genera Bactromyces, Carouxella, Caudomyces, Gauthieromyces, Klastostachys, Tectimyces, Zygopolaris and Zygopolaropsis ...
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... are no appendages in the genera Bactromyces, Carouxella, Caudomyces, Gauthieromyces, Klastostachys, Tectimyces, Zygopolaris and Zygopolaropsis ( Lichtwardt 2004, Valle 2004). Trichospores can also bear a collar at the basal end, which are cellular remnants of the generative cell where it was attached, or they can be collarless ( Lichtwardt et al. 2001a) (Figs 12, 13). ...
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... (Horn 1989a, b, c). During germination, after ingestion by a suitable host, the sporangiospore wall separates from the sporangium (or merosporangium) wall and slides through it until it is released into the gut lumen ( Moss and Lichtwardt 1976, Horn 1989a). Only some species in two genera do not follow this process: Spartiella (Valle 2004) ( Fig. 13g) and Orphella (within Orphellales) (Valle 2004), since they release the sporangial content into the environment, not necessarily after consumption of the trichospore by the host. Carouxella is also peculiar in that it has an unbranched thallus with disarticulating generative cells bearing trichospores (Manier & Lichtwardt ...
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... propagules from the basal cell. On the other hand, the genus Ejectosporus, associated with plecoptera, produces non-deciduous vegetative spores at the upper section of the thallus that also extrude their contents endogenously (Strongman 2005(Strongman , 2007 The sexual reproduction of Harpellales is by means of the zygospores in zygosporangia (Fig. 13h, i), which are usually biconial or more rarely conical (in Carouxella, Lancisporomyces, Plecopteromyces and Zygopolaris), thick-walled resistant sporangia containing the zygote. The shape of these unique zygospores may be an adaptation for a rapid circulation and germination within the host gut and, like trichospores, these can also have ...
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... thick wall found in most zygospores may also serve a protective function allowing these spores to survive a period of time in the system outside a host. The zygospores grow on a specialized cell called a zygosporophore (Fig 13h, arrow). Zygospore formation often occurs near the end of a molting cycle in the host ( Lichtwardt et al. 2001a), to ensure fungal survival and propagation after ecdysis (Valle 2010), and it is believed that the molting hormone of the host, or ecdysone, stimulates the sexual process in endosymbiont fungi ( Lichtwardt et al. 2001a). ...
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... that the molting hormone of the host, or ecdysone, stimulates the sexual process in endosymbiont fungi ( Lichtwardt et al. 2001a). The effect of ecdysone on an endosymbiont life cycle has been studied in the mosquito Adedes aegypti infected with the fungus Coelomomyces stegomyiae (Lucarotti 1992). Harpellales can reproduce homothallically (Fig. 13h) or heterothallically. In heterothallic species, the zygospores arise from the middle of a conjugating tube between conjugants, or in a branch next to it; more rarely they may grow on a distant branch (Valle 2004). In homothallic species, particular cells accompanying the zygospore may be present, as in the case of Genistellospora ...
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... process of the inner sporangiospore will proceed. A mucilaginous holdfast is then excreted which secures the thallus initial to the gut lining of the host ( Lichtwardt et al. 2001a, Tretter et al. 2013). The thallus develops, and ultimately, at maturity, it sporulates producing asexual trichospores or sexual zygospores, as described before. (Fig. 14). Unsurprisingly, given this short time for growth and sporulation there are many fewer species in the Harpellaceae with described zygospores ( Lichtwardt et al. ...
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... most cases, the fixation element of Harpellales does not pierce the intestinal membrane ( Fig. 12), i.e., there is no tissue invasion, except in a few species of the genus Smittium, such as S. heterosporum (Valle & Santamaria 2004), S. morbosum (Dubitskii 1978, Sweeney 1981a, S. longisporum (Williams et al. 1982) and S. perforatum (Williams & Lichtwardt 1987, Lichtwardt et al. 1997). Among these cases, only S. morbosum is pathogenic ...
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... the most common, cosmopolitan, and species-rich genera of Harpellales, we find the branched Smittium (Figs 11d, 12c, d, 13e) and the unbranched Stachylina (Fig. 11a), mostly associated with Simuliidae, Chironomidae and Culicidae. Many species in Smittium can be cultured and numerous studies focusing on different aspects of their biology, taxonomy and phylogeny have 242 been published on members of this genus living in the hindgut of their hosts (see Lichtwardt et al. 2001a, b). ...
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... the most common, cosmopolitan, and species-rich genera of Harpellales, we find the branched Smittium (Figs 11d, 12c, d, 13e) and the unbranched Stachylina (Fig. 11a), mostly associated with Simuliidae, Chironomidae and Culicidae. Many species in Smittium can be cultured and numerous studies focusing on different aspects of their biology, taxonomy and phylogeny have 242 been published on members of this genus living in the hindgut of their hosts (see Lichtwardt et al. 2001a, b). Stachylina is also ...
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... in the hindgut of their hosts (see Lichtwardt et al. 2001a, b). Stachylina is also a speciose genus, with 43 described species, most of them associated with Chironomidae midges, more rarely with Thaumaleidae, Blepharicidae and Psychodidae (Williams & Lichtwardt 1984, Lichtwardt & Williams 1990, Sato & Degawa 2018. Genistellospora (branched) (Fig. 11l) and Harpella (unbranched) are not as diverse as Smittium or Stachylina but are also common, cosmopolitan genera inhabiting the hindgut and midgut, respectively, of Simuliidae larva. Among the more common genera associated with Plecoptera we find Lancisporomyces (Figs 12a, 13f) Genistelloides and Ejectosporus and among frequent ...
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... (branched) (Fig. 11l) and Harpella (unbranched) are not as diverse as Smittium or Stachylina but are also common, cosmopolitan genera inhabiting the hindgut and midgut, respectively, of Simuliidae larva. Among the more common genera associated with Plecoptera we find Lancisporomyces (Figs 12a, 13f) Genistelloides and Ejectosporus and among frequent symbionts of Ephemeroptera we find Legeriomyces (Fig. 13d) and, although not as common and widespread, Glotzia and Graminella, among others (see Lichtwardt et al. 2001a). Other hosts not as well studied but also house endosymbionts, are Trichoptera (caddisflies), including a species of Smittium and one of Legeriomyces (Strongman & White 2019). ...
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... not as diverse as Smittium or Stachylina but are also common, cosmopolitan genera inhabiting the hindgut and midgut, respectively, of Simuliidae larva. Among the more common genera associated with Plecoptera we find Lancisporomyces (Figs 12a, 13f) Genistelloides and Ejectosporus and among frequent symbionts of Ephemeroptera we find Legeriomyces (Fig. 13d) and, although not as common and widespread, Glotzia and Graminella, among others (see Lichtwardt et al. 2001a). Other hosts not as well studied but also house endosymbionts, are Trichoptera (caddisflies), including a species of Smittium and one of Legeriomyces (Strongman & White ...
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... Girbal 1998, Valle & Santamaria 2005. The set of 4-(or 3) cells in the trichospore dispersion unit (Figs 17, 18) are now routinely incorporated in the description of new species, as these are considered of important ontogenic and taxonomic significance (Valle & Santamaria 2005, White et al. 2018). Trichospores are straight (e.g., O. catalaunica) (Fig. 16e), allantoid (e.g., O. haysii, O hiemalis) (Fig. 16d) or helicoidal (e.g., O. pseudoavalonensis) (Fig. 16a, b) and sometimes the spore head protrudes from the gut out of the anus before detaching from the thallus for dispersion from an infested host ( Valle 2004, White et al. ...
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... 3) cells in the trichospore dispersion unit (Figs 17, 18) are now routinely incorporated in the description of new species, as these are considered of important ontogenic and taxonomic significance (Valle & Santamaria 2005, White et al. 2018). Trichospores are straight (e.g., O. catalaunica) (Fig. 16e), allantoid (e.g., O. haysii, O hiemalis) (Fig. 16d) or helicoidal (e.g., O. pseudoavalonensis) (Fig. 16a, b) and sometimes the spore head protrudes from the gut out of the anus before detaching from the thallus for dispersion from an infested host ( Valle 2004, White et al. ...
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... 17, 18) are now routinely incorporated in the description of new species, as these are considered of important ontogenic and taxonomic significance (Valle & Santamaria 2005, White et al. 2018). Trichospores are straight (e.g., O. catalaunica) (Fig. 16e), allantoid (e.g., O. haysii, O hiemalis) (Fig. 16d) or helicoidal (e.g., O. pseudoavalonensis) (Fig. 16a, b) and sometimes the spore head protrudes from the gut out of the anus before detaching from the thallus for dispersion from an infested host ( Valle 2004, White et al. ...
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... most distinctive elements of Orphellales are, undoubtedly, the sexual spores (zygospores) and their accompanying cells (Valle & Santamaria 2005) (Figs 16g, f, 17), which are absolutely different from all other known Zoopagomycota and also from related Harpellales (Valle & Santamaria 2005, White et al. 2018). The zygospores also form a dispersion unit, being slightly different from the trichospore dispersion unit. ...
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... a dispersion unit, being slightly different from the trichospore dispersion unit. There are other cells associated with the development of zygospores which are not detached with the dispersion unit; these cells are key for a clear identification of zygospores in those species where both trichospores and zygospores have a similar 243 morphology ( Fig. 17) (Valle & Santamaria 2005). Zygospores are typically helicoidal (as in O. avalonensis) or semi-helicoidal (as in O. catalaunica) ( White et al. 2018) (Fig. 16g, f). c Released trichospore circulating towards the anus to be expelled outside the host. d Trichospore in the aquatic environment, the sticky appendages will attach the spore in ...
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... not detached with the dispersion unit; these cells are key for a clear identification of zygospores in those species where both trichospores and zygospores have a similar 243 morphology ( Fig. 17) (Valle & Santamaria 2005). Zygospores are typically helicoidal (as in O. avalonensis) or semi-helicoidal (as in O. catalaunica) ( White et al. 2018) (Fig. 16g, f). c Released trichospore circulating towards the anus to be expelled outside the host. d Trichospore in the aquatic environment, the sticky appendages will attach the spore in the host environment. e The trichospore is ingested by the appropriate host; the inner spore is extruded and anchored to the gut lining by adhesive holdfast ...
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... species. Zygospores were initially misidentified as unusually large trichospores, due to their similarity in appearance to the asexual spores (Williams & Lichtwardt 1987, Lichtwardt et al. 2001b). However, zygospore-associated cells (Fig. 17) and conjugation in homothallic species of Orphella were consistent and similar with those of homothallically formed zygospores in some species of Harpellales, such as Genistellospora homothallica. This evidence was the key to recognizing the zygosporic nature of those unusually large spores (Valle 2004, Valle & Santamaria 2005, White ...
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... Capnidae, Leuctridae, Nemouridae and more rarely, Taeniopterygidae. Their life cycle and relationship with the host is the same as is known for Harpellales, as far as we know. The most noticeable characteristic of the spores and related cells in the dispersion unit is the presence of a long terminal cell, both in the sexual and asexual spores (Fig. 16a, b, g). This terminal cell is thin and can be very long, surpassing 200 µm in length, when most spores measure about 20-50 µm. The terminal cell, with a sticky consistency, has the same function as the appendages of spores in Harpellales, i.e., reduce the effect of water flow and downstream drift (Valle 2004, Valle & Santamaria 2005, White ...
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... have branched thalli and a differentiated basal cell which is of taxonomic importance ( Lichtwardt et al. 2001a). In fact, Asellaria species are identified primarily by holdfast characteristics (Lichtwardt & Moss 1984, Valle 2006, Valle & Cafaro 2008, while thallial and sporic features may complement the information for classification (Fig. 17). These two genera produce arthrospore-like cells produced by fragmentation of the branches (Fig. 17). According to Lichtwardt et al. (2001a), the arthrospores may be the equivalent of generative cells in Harpellales, since they develop a kind of an outgrowth that somewhat resembles the trichospores of Harpellales, although the complete ...
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... et al. 2001a). In fact, Asellaria species are identified primarily by holdfast characteristics (Lichtwardt & Moss 1984, Valle 2006, Valle & Cafaro 2008, while thallial and sporic features may complement the information for classification (Fig. 17). These two genera produce arthrospore-like cells produced by fragmentation of the branches (Fig. 17). According to Lichtwardt et al. (2001a), the arthrospores may be the equivalent of generative cells in Harpellales, since they develop a kind of an outgrowth that somewhat resembles the trichospores of Harpellales, although the complete development of these structures has not been observed. Terminal or intercalary spherical ...
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... the sticky spores in the freshwater environment. For the same purpose, aquatic Laboulbeniales also display more frequently than other species two morphological features: preapical outgrowths with different shapes and sizes, that are thought to function as levers facilitating release of the spores only during mating of the host-insects (example in Fig. 19a), and outgrowths at the base of the thalli, commonly called "buffer cells" (example in Fig. 19b), that are thought to keep the thalli in the correct position to come in contact with the right portion of the body of insects of same species during mating (mainly) or other direct contacts. It is interesting to note in this regard that ...
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... display more frequently than other species two morphological features: preapical outgrowths with different shapes and sizes, that are thought to function as levers facilitating release of the spores only during mating of the host-insects (example in Fig. 19a), and outgrowths at the base of the thalli, commonly called "buffer cells" (example in Fig. 19b), that are thought to keep the thalli in the correct position to come in contact with the right portion of the body of insects of same species during mating (mainly) or other direct contacts. It is interesting to note in this regard that preapical outgrowths are not common among the hundreds of "terrestrial" species of the genus ...
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... Many freshwater ascomycetous species produce asci with large apical rings, ascospores with various sheaths, appendages, or wall ornamentations, which probably function in ascospore dispersal and/or attachment ( Wong et al. 1998). For example, Annulatascus velatispora, a common freshwater lignicolous taxon, possesses asci with a large apical ring (Fig. 21a), which may help in the ejection of ascospores from asci (Fig. 21a); Aqualignicola vaginata and Phaeonectriella appendiculata produce ascospores with a sticky sheath and appendages (Fig. 21b, c), which may help the spores attach to ...
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... rings, ascospores with various sheaths, appendages, or wall ornamentations, which probably function in ascospore dispersal and/or attachment ( Wong et al. 1998). For example, Annulatascus velatispora, a common freshwater lignicolous taxon, possesses asci with a large apical ring (Fig. 21a), which may help in the ejection of ascospores from asci (Fig. 21a); Aqualignicola vaginata and Phaeonectriella appendiculata produce ascospores with a sticky sheath and appendages (Fig. 21b, c), which may help the spores attach to ...
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... and/or attachment ( Wong et al. 1998). For example, Annulatascus velatispora, a common freshwater lignicolous taxon, possesses asci with a large apical ring (Fig. 21a), which may help in the ejection of ascospores from asci (Fig. 21a); Aqualignicola vaginata and Phaeonectriella appendiculata produce ascospores with a sticky sheath and appendages (Fig. 21b, c), which may help the spores attach to ...
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... hyphomycetous wood decay fungi often produce spiral or branched conidia, which are thought to aid in flotation in water or act as anchors and allow their entrapment to substrata (Ingold 1942, Wong et al. 1998). Helicomyces roseus and Pleohelicoon richonis, for example, produce spiral conidia (Fig. 21d, e), whereas Tetraposporium sp. develops branched conidia (Fig. 21f). ...
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... wood decay fungi often produce spiral or branched conidia, which are thought to aid in flotation in water or act as anchors and allow their entrapment to substrata (Ingold 1942, Wong et al. 1998). Helicomyces roseus and Pleohelicoon richonis, for example, produce spiral conidia (Fig. 21d, e), whereas Tetraposporium sp. develops branched conidia (Fig. 21f). ...
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... major economic significance of freshwater fungi was in the decay of wooden slats in water cooling towers, where water from electrically generating turbines was cooled and recycled (Savory 1954a). This led to the characterization of soft rot attack of wood by Savory (1954a, b), which led to a major study of wood decay fungi in water cooling towers by Eaton & Jones (1971a, b) and Jones (1972). The decay of wood was rapid due to the elevated temperature in cooling towers, with weight loss of beech and Scots pine test blocks of 60 and 53%, respectively, after 108 weeks of exposure (Eaton and Jones 1971b). ...
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... throughput sequencing approaches have enabled detailed, semi-quantitative analysis of fungal communities in large sample sets and provide ecological information that outperforms earlier approaches in terms of detail and magnitude ( Lindahl et al. 2013), even at a global scale ( Větrovský et al. 2020Větrovský et al. , Tedersoo et al. 2021). High throughput sequencing approaches are based on short reads (< 550 base pairs -bp) and fall under two broad categories, sequence by ligation and sequence by synthesis (Goodwin et al. 2016). The sequence by ligation approach is a straightforward enzymatic method of sequencing DNA that involves the hybridization and ligation of labelled probe and anchor sequences to a DNA strand ( Ho et al. 2011). ...
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... throughput sequencing platforms follow a similar pipeline in general which involves template preparation, clonal amplification, followed by parallel sequencing ( Reuter et al. 2015). Here we describe each step for fungal HTS methods focusing on environmental freshwater sampling ( Fig. 31), their challenges and the recommended best practices. We also performed literature review on the bibliographic databases from Web of Science and Google Scholar on 11/03/2022 using the keywords "freshwater" AND "next-generation sequencing" OR "high throughput sequencing". Subsequently, the literature was filtered, selecting only ...
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... positive control ensures that the organisms can be sufficiently extracted with the used methods whereas a negative control ensures that no large-scale cross-contamination between samples takes place ( Hornung et al. 2019). It is recommended to choose the most diverse mock community for the positive control to prevent overfitting of the protocol (Hornung et al. 2019). Quantitative real-time PCR (qPCR) can be used to optimize extraction protocols and PCR conditions as well as to pre-screen samples ( Forootan et al. 2017). ...
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... distance between communities can be analyzed based on global alignment using UniFrac which can exploit similarities and differences between species (Hamady et al. 2010). However, such a method is more common with bacterial data since methods based on global alignments are not recommended for the ITS region due to its high variability and length (Tedersoo & Lindahl 2016). ...
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... hilldiv package can be used for diversity analyses using OTUs and ASVs (Alberdi & Gilbert 2019). The iNEXT package can be used to quantify species diversity in a sample by using species richness, Shannon diversity and Simpson diversity which are the most widely used species diversity measures (Hsieh et al. 2016). The metacoder package can be used to evaluate taxonomic coverage or displaying differences in taxon abundance between communities ( Foster et al. 2017). ...
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... but the knowledge regarding the metal response or its effects is more profound at the lower levels of biological organization. It may be because the aquatic hyphomycetes ecotoxicological studies at the lower levels could be easily visualized using microcosm studies, hence promoting a more in-depth understanding at the lower level (Table 11, Fig. ...
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... the geographical extent and number of the studies revolving around the impact of metals on aquatic hyphomycetes were limited (Fig. 41), lately, the significance of the effects of metals at the ecosystem level has been receiving a lot of attention (see Ferreira et al. 2016). However, these studies are challenging as many factors are regional acting at different scales. Some of the factors can impact the ecosystem two-fold due to metal concentration and sensitivity. ...
Citations
... Braun) Rabenh. as the type species and currently, more than 220 species are recognised under this generic concept (4,5). Traditionally, Rhizophydium was classified within the order Chytridiales Cohn (4,6). ...
In the present study, seven chytrid species from the genus Rhizophydium, specifically Rhizophydium annulatum, R. coronum, R. condylosum, R. elyense, R. keratinophilum, R. sphaerotheca and R. utriculare were collected from north India and are briefly described. The descriptions are accompanied by photographs illustrating their morphological and taxonomical characteristics. Notably, R. annulatum, R. elyense and R. utriculare represent the first records of these species in the Indian mycobiota.
... The comprehensive collection of freshwater substrates across Asia, particularly in regions like China and Thailand, has significantly advanced the discovery of freshwater fungi, including many species new to science (Luo et al. 2019;Dong et al. 2020;Hyde et al. 2021;Calabon et al. 2022;Calabon et al. 2023;Dong et al. 2023;Hyde et al. 2023;Yang et al. 2023). This ongoing effort also facilitates the recollection of previously known fungal taxa that lacked molecular data (Luo et al. 2019;Calabon et al. 2020Calabon et al. , 2021Dong et al. 2020). ...
... Most species, such as A. bellaspora, A. decorospora, A. naponensis, and A. ovalispora, are known only from their type localities, where their holotypes were originally described ( Figure 3) (Hu et al. 2010b;Ferrer et al. 2011;Raja et al. 2012). This underscores the critical need for ongoing exploration in freshwater ecosystems, particularly in underexplored or unexplored regions, to fully elucidate fungal diversity and distribution (Calabon et al. 2023). ...
... The continued collection of specimens and revision of fungal taxa not only deepens our understanding of fungal systematics but also provides essential insights into ecological interactions and evolutionary processes (Calabon et al. 2023). Furthermore, the incorporation of molecular data, especially for species where such data is lacking, is crucial for resolving phylogenetic relationships and refining classifications. ...
This study investigates lignicolous freshwater fungi in Thailand, resulting in the collection of Ascominuta lignicola. Sequence data from the large subunit (LSU) and small subunit (SSU) ribosomal RNA genes revealed that A. lignicola is phylogenetically positioned within the Natipusilla clade (Natipusillaceae, Natipusillales). Morphologically, Ascominuta exhibits similarities to Natipusilla, characterised by small ascomata, few to absent pseudoparaphyses, subglobose asci, and predominantly one-septate ascospores surrounded by a gelatinous sheath if present. In accordance with the principle of priority, species previously classified under Natipusilla (N. bellaspora, N. decorospora, N. limonensis, and N. naponensis) were transferred to Ascominuta. This paper provides detailed descriptions and illustrations of Ascominuta lignicola, along with an updated phylogenetic backbone for the order Natipusillales.
... Non-phialidic fungi in Chaetosphaeriaceae are predominantly characterized by sporidesmium-like asexual morphs (Ellis 1971(Ellis , 1976Wu and Zhuang 2005;Wu and Diao 2022;Yang et al. 2023;Delgado et al. 2024). These taxa are primarily saprobic, occurring on various plant substrates in both terrestrial and aquatic habitats, with some species also found in soil or as fungicolous taxa (Hughes and Kendrick 1968;Perera et al. 2016;Hyde et al. 2018;Réblová et al. 2020Réblová et al. , 2021dWu and Diao 2022;Zhang et al. 2022;Calabon et al. 2023;Yang et al. 2024;Zhang et al. 2024). ...
Anamorphic chaetosphaeriaceous fungi exhibit high morphological variability and are distributed worldwide across terrestrial and aquatic habitats. During an ongoing taxonomic study of microfungi, two intriguing chaetosphaeriaceous hyphomycetes were collected from dead wood and dead bamboo stems in China and Thailand. A polyphasic approach, combining morphological characteristics and phylogenetic analysis of LSU and ITS sequence data, revealed that these fungi represent two new genera within Chaetosphaeriaceae. Pseudolomaantha and Submultiguttulispora are proposed for these new genera, and they exhibit non-phialidic and phialidic asexual morphs, respectively. Pseudolomaantha thailandicagen. et sp. nov. is characterized by a sporidesmium-like asexual morph with macronematous, mononematous conidiophores; monoblastic conidiogenous cells, and pyriform to obclavate, rostrate conidia bearing an apical appendage. Submultiguttulispora multiseptatagen. et sp. nov. is distinguished by macronematous, mononematous conidiophores, mono- to polyphialidic conidiogenous cells, and fusiform or ellipsoidal-fusiform, pale brown to olive green to brown conidia with filiform, hyaline appendages at both ends. Detailed descriptions, illustrations, and notes on the new collections are provided, along with a key to non-phialidic hyphomycetous genera in Chaetosphaeriaceae.
... Wurzbacher et al. 2016). Aquatic fungi span all fungal lineages, including poorly studied zoosporic fungi, for example, Cryptomycota and Chytridiomycota (Picard 2017;Tedersoo et al. 2018), and the well-known aquatic hyphomycetes, an ecological group consisting of predominantly ascomycetes (Shearer et al. 2007) belonging to the fungal classes of Leotiomycetes, Sordariomycetes, Dothideomycetes, Orbiliomycetes and Pezizomycetes (Baschien 2006;Belliveau and Bärlocher 2005;Calabon et al. 2023;Campbell, Shearer, and Marvanová 2006;Campbell, Marvanová, and Gulis 2009). Despite the recognised importance of the aquatic hyphomycetes as the major microbial decomposers of plant litter in streams (Gessner et al. 2007), the taxonomic position of many species remains unknown. ...
Known for its remarkable diversity and ecological importance, the fungal kingdom remains largely unexplored. In fact, the number of unknown and undescribed fungi is predicted to exceed the number of known fungal species by far. Despite efforts to uncover these dark fungal taxa, we still face inherent sampling biases and methodological limitations. Here, we present a framework that combines taxonomic knowledge, molecular biology and data processing to explore the fungal biodiversity of enigmatic aquatic fungal lineages. Our work is based on serial screening of environmental fungal cells to approach unknown fungal taxa. Microscopic documentation is followed by DNA analysis of laser micro-dissected cells, coupled with a ribosomal operon barcod-ing step realised by long-read sequencing, followed by an optional whole genome sequencing step. We tested this approach on a range of aquatic fungal cells mostly belonging to the ecological group of aquatic hyphomycetes derived from environmental samples. From this initial screening, we were able to identify 60 potentially new fungal taxa in the target dataset. By extending this methodology to other fungal lineages associated with different habitats, we expect to increasingly characterise the molecular barcodes of dark fungal taxa in diverse environmental samples. This work offers a promising solution to the challenges posed by unknown and unculturable fungi and holds the potential to be applied to the diverse lineages of undescribed microeukaryotes.
... Since 1996, extensive research has led to the description of over 3,870 freshwater fungal species, primarily ascomycetes (Calabon et al. 2022;Goh and Hyde 1996). The discovery of new taxa continues to accelerate, with no signs of slowing down (Calabon et al. 2023). ...
... In freshwater ecosystems, Trichoderma species play a crucial ecological role through their lignocellulolytic activity, which allows them to colonize and degrade lignocellulosic substrates, even in submerged aquatic habitats (Savory 1954;Calabon et al. 2023;Huang et al. 2024). The presence of saprobic Trichoderma in freshwater environments has been well-documented across several regions. ...
Trichoderma protrudens Samuels & P. Chaverri was originally described from the trunk of Theobroma cacao L. in Kerala, India, in 2008. Morphologically, it is defined by trichoderma‑like conidiophores bearing subulate or lageniform phialides, green subglobose to obovoidal conidia, and the presence of chlamydospores in culture. Multilocus phylogenetic analyses based on ITS, rpb2, and tef1-α sequence data confirmed the iden‑ tity of the isolates from the Philippines as T. protrudens, with robust support values (100% ML, 1.00 BPP) clustering them with the holotype CBS 121320. This study represents the first global record of T. protrudens in a freshwater ecosystem, expanding this species’ known ecological range into aquatic environments. These findings emphasize the ecological versatility of T. protrudens and underscore the importance of further investigations into the fungal diversity of freshwater habitats.
... The number of hyphomycetes introduced over the past decade has increased substantially, indicating that their diversity is rather high (Hyde et al. 2020Bhunjun et al. 2022;Manawasinghe et al. 2022;Calabon et al. 2023;Liu et al. 2024b;Tian et al. 2024;Zhang et al. 2024). Hyphomycetes have a ubiquitous distribution in aquatic and terrestrial habitats, occurring on different substrates in tropical and subtropical regions (Seifert et al. 2011;Bao et al. 2021;Diao 2022, 2023;Dong et al. 2023;Senanayake et al. 2023;Yang et al. 2023;Liu et al. 2024a, b). ...
Xiuguozhangia species are dematiaceous hyphomycetes that are characterised by acropleurogenous, dictyoseptate, campanulate or cheiroid, and brown to dark brown conidia that are composed of several layers of cells radiating from a protuberant basal cell, and mostly seen with appendages arising from the apical cells. The genus was introduced based on morphology to accommodate five of the six Piricaudiopsis species that exhibited holoblastic conidial ontogeny. Xiuguozhangia was referred to as Ascomycota genus incertae sedis as it was challenging to resolve its taxonomic placement based solely on the available morphological data (no DNA sequence data was previously available). In this study, we provide DNA sequence data for LSU, ITS, SSU, TEF1, and RPB2 for our isolates, collected from Broussonetia papyrifera (Moraceae) in northern Thailand. Based on morphology, we classify our isolates as Xiuguozhangia. Since they form a sister lineage to Pseudoberkleasmium, we place Xiuguozhangia in Pseudoberkleasmiaceae (Pleosporales). Within Xiuguozhangia, we establish these two isolates as a new taxon, Xiuguozhangia broussonetiae, in view of the presence of new conidiogenous cells developing from subtending cells. Xiuguozhangia broussonetiae differs from the extant species in the genus as it has longer conidiophores that are sometimes branched, comprising numerous septa, and its appendages are mostly untapered (sometimes tapering) towards the tips, a feature not observed in other Xiuguozhangia species. This is the first study to provide DNA sequence data and phylogenetic relationships for Xiuguozhangia. Furthermore, we analysed selected DNA sequence data and provided an updated phylogenetic tree incorporating all families (with representative genera) of Pleosporales.
... In contrast, only around 3900 species are from freshwater environments. It shows the significance of continued exploration and suggests that vast freshwater ascomycetes remain undiscovered [8,9]. Current research on lignicolous freshwater fungi is predominantly focused on those of Asia, particularly in countries such as China and Thailand [1,[10][11][12][13][14][15][16][17][18]. ...
Yuanjiang River (Red River) is one of the six major water systems in Yunnan Province, which originates from western Yunnan Province. This river system features numerous tributaries, complex terrain, and abundant natural resources. During the investigation on the diversity of lignicolous freshwater fungi in the Yuanjiang River, nine species were collected and identified, five belonging to Dothideomycetes and four to Sordariomycetes. Based on morphology and multigene phylogenetic analyses, four species, namely, Aquadictyospora aquatica, Dictyosporium fluminicola, Myrmecridium submersum, and Neomyrmecridium fusiforme, are described as new species. Dictyocheirospora aquadulcis is reported as a new national record, and Myrmecridium hydei is reported as a new habitat record. Dictyocheirospora rotunda, Halobyssothecium aquifusiforme, and Pseudohalonectria lutea were known earlier from freshwater habitats, but we described them in detail in this paper. This study contributes significantly to the understanding of the diversity of lignicolous freshwater fungi in southwestern China.
... Freshwater fungi exhibit significant ecological diversity, thriving on various substrates, including submerged wood, freshwater foam, herbaceous materials, insects, leaves, sediments, other organic matter, and living plants (Hu et al. 2013;Shen et al. 2022;Luo et al. 2019;Calabon et al. 2023;Yang et al. 2023). These freshwater fungi belong to Dothideomycetes, Eurotiomycetes, Laboulbeniomycetes, Leotiomycetes, Orbiliomycetes, Pezizomycetes, and Sordariomycetes (Hu et al. 2013;Li et al. 2017;Calabon et al. 2022;Hyde et al. 2023). ...
... Fungi in aquatic environments are recognized for their role in decomposing allochthonous organic matter, transforming it into nutrients accessible to other trophic levels in the freshwater food web, such as zooplankton and bacteria (Krauss et al., 2011;Bärlocher, 2016;Grossart et al., 2019). Despite their important role, less than 10% of the estimated 1.5 million fungal species on Earth have been characterized, with just 3,000-4,000 known true aquatic fungi (Ittner et al., 2018;Lepere et al., 2019;Calabon et al., 2023). The low number of identified aquatic fungal species is partly due to the challenges in culturing them and the limitations of traditional in situ morphological characterization methods (Bärlocher, 2016). ...
... (Calabon et al., 2020). However, the limited entries in these databases, compared to the broader known diversity of aquatic fungal species (Calabon et al., 2023), likely led to an underestimation of aquatic fungi in our dataset. Despite this, we identified 138 OTUs across 58 genera potentially containing aquatic fungal species at low abundance (3% of the total abundance). ...
Introduction
Fungi are essential to the aquatic food web, nutrient cycling, energy flow, and ecosystem regulation. Fungal community structures in water can be influenced by adjacent terrestrial environments, which drive and control some ecosystem services they provide. However, the roles of freshwater fungal communities remain underexplored compared to bacterial communities in this context.
Methods
We assessed the impact of anthropological and environmental factors on freshwater mycobiota in an agriculturally dominated water basin in eastern Ontario, Canada. We undertook bi-weekly surface water sampling from 2016 to 2021 and conducted fungal internal transcribed spacer 2 (ITS2) metabarcoding on the samples, complemented by ancillary data, including water physicochemical properties, upstream land use, hydrology, and weather conditions.
Results
Our study yielded 6,571 OTUs from 503 water samples, spanning 15 fungal phyla, dominated by Ascomycota, Basidiomycota, and Chytridiomycota. Agricultural land use was associated with decreased mycobiota alpha diversity and distinct fungal communities were observed at agricultural drainage ditch and mixed-land use sites compared to a forested site that had minimal anthropogenic activities in catchment. Notably, river discharge emerged as a predominant influencer of both community diversity and composition, likely amplified by precipitation-induced erosion and drainage from adjacent terrestrial environments.
Discussion
Water physicochemical properties, including stream fungicide levels, explained a small proportion of the variation in mycobiota communities, underscoring the significance of unmeasured factors, alongside stochastic community assembly processes. Nevertheless, stream mycobiota demonstrated functional resilience for critical ecological processes under different environmental conditions. Altogether, these results highlight the complex interplay of factors influencing the freshwater mycobiota, which is essential for elevated understanding of the ecosystem services these fungi provide.
... Various fungal species can decolorize various colors [12,13]. Numerous fungal genera have been utilized in their living or deactivated state [14]. White-rot fungi, specifically Phanerochaete chrysosporium have been extensively documented for their effectiveness in removing color from textile wastewater [15][16][17][18][19][20][21][22]. ...
