Tropical stream microcosms of isolated fungal species suggest nutrient enrichment does not accelerate decomposition but might inhibit fungal biomass production.

Terrestrial leaf litter is an essential energy source in forest streams and in many tropical streams, including Cerrado, litter undergoes biological decomposition mainly by fungi. However, there is a limited understanding of the contribution of isolated fungal species to in-stream litter decomposition in the tropics. Here we set a full factorial microcosms experiment using four fungal species (Aquanectria penicillioides, Lunulospora curvula, Pestalotiopsis submerses, and Pestalotiopsis sp.) incubated in isolation, two litter types (rapid and slow decomposing litter) and two nutrient levels (natural and enriched), all characteristics of Cerrado streams, to elucidate the role of isolated fungal species on litter decomposition. We found that all fungal species promoted litter mass loss but with contributions that varied from 1% to 8% of the initial mass. The fungal species decomposed 1.5 times more the slow decomposing litter and water nutrient enrichment had no effect on their contribution to mass loss. In contrast, fungal biomass was reduced by nutrient enrichment and was different among fungal species. We showed fungal contribution to decomposition depends on fungal identity and litter type, but not on water nutrients. These findings suggest that the identity of fungal species and litter types may have more important repercussions to in-stream decomposition than moderate nutrient enrichment in the tropics.

Acrogenospora terricola sp. nov., a fungal species associated with seeds of pioneer trees in the soil seed bank of a lowland forest in Panama.

As currently circumscribed, Acrogenospora (Acrogenosporaceae, Minutisphaerales, Dothideomycetes) is a genus of saprobic hyphomycetes with distinctive conidia. Although considered common and cosmopolitan, the genus is poorly represented by sequence data, and no neotropical representatives are present in public sequence databases. Consequently, Acrogenospora has been largely invisible to ecological studies that rely on sequence-based identification. As part of an effort to identify fungi collected during ecological studies, we identified strains of Acrogenospora isolated in culture from seeds in the soil seed bank of a lowland tropical forest in Panama. Here we describe Acrogenospora terricola sp. nov. based on morphological and phylogenetic analyses. We confirm that the genus has a pantropical distribution. The observation of Acrogenospora infecting seeds in a terrestrial environment contrasts with previously described species in the genus, most of which occur on decaying wood in freshwater environments. This work highlights the often hidden taxonomic value of collections derived from ecological studies of fungal communities and the ways in which rich sequence databases can shed light on the identity, distributions and diversity of cryptic microfungi.

Diversity of saprotrophic filamentous fungi on Araucaria angustifolia (Bertol.) Kuntze (Brazilian pine).

The biodiversity of filamentous fungi and their ecological relationships in the context of decaying Araucaria angustifolia (an endangered conifer) substrates are still mostly unknown. The present study aimed to investigate the diversity of saprotrophic filamentous fungi, based on morphological identification, associated with A. angustifolia, in addition to assessing possible saprobic/plant affinity relationship, and verifying whether the study areas and substrates affect the composition of the mycobiota. A total of 5000 substrates (decaying needles and twigs) were collected during five expeditions (2014/2015) to two areas: São Francisco de Paula National Forest (FLONA-SFP) and São Joaquim National Park (PARNA-SJ), Brazil. A total of 135 species distributed among 85 genera, 40 families, nine classes, 24 orders, three subphyla, and two phyla were identified. One new genus and five new species that were previously described, and six rare species and five species with affinity for A. angustifolia were also recorded. The twigs showed a community of fungi with greater richness and dominance. Conversely, the values of abundance, Simpson's diversity index, and evenness were lower than those determined for needles. In terms of the study areas, FLONA-SFP showed higher values of richness, abundance, Simpson's diversity index, and evenness than PARNA-SJ. Principal coordinate analysis and similarity percentage analysis showed the influence of both substrate factors and areas in the composition of the fungal communities. The presence of new, rare, and affinity-related species reinforces the study of fungi in the context of the conservation of this conifer, as these species are threatened by co-extinction.

Shredders prefer soft and fungal-conditioned leaves, regardless of their initial chemical traits / Fragmentadores preferem folhas macias e condicionadas por fungos, independente da sua qualidade química inicial

Through field and laboratory experiments we investigated the effects of leaf traits of two tree species and microbial conditioning on the abundance, biomass, and feeding preference of a typical macroinvertebrate shredder. In the field, we compared the association of Phylloicus (Calamoceratidae, Trichoptera) with two tree species commonly found in riparian zones, which are representative of high and low nutritional quality, respectively: Nectandra megapotamica and Chusquea tenella. In the laboratory, we investigated the feeding preference of Phylloicus using unconditioned leaves and leaves conditioned by aquatic fungi. The same tree species used in the field experiment were used in the laboratory. Initially, C. tenella leaves were proved to be more nutritious and softer, while N. megapotamica leaves were harder and more lignified. The shredders preferred conditioned leaf detritus of reduced toughness (field: C. tenella; laboratory: N. megapotamica, both conditioned for 14 days). These leaf traits seem to be crucial for the choice process of Phylloicus. After 14 days, N. megapotamica leaves showed a decreased toughness associated with the microbial conditioning, which explained its consumption rate by Phylloicus. In both field and laboratory experiments, we found evidence that Phylloicus is a selective feeding shredder, and that the leaf traits, especially leaf structure (e.g., leaf toughness and lignin content), determine its association and preferences.(AU)

Nós investigamos em experimento de campo e de laboratório os efeitos das características foliares e condicionamento microbiano de duas espécies de árvores na abundância, biomassa e preferência alimentar de um fragmentador típico. No experimento de campo, comparamos a associação do Phylloicus (Calamoceratidae, Trichoptera) entre duas espécies vegetais, comumente encontradas em zonas ripárias, que são representativas de alta e baixa qualidade nutricional, respectivamente: Nectandra megapotamica e Chusquea tenella. Em experimento de laboratório, investigamos a preferência alimentar de Phylloicus, usando folhas condicionadas e não condicionadas pelos fungos aquáticos. As mesmas espécies vegetais usadas no experimento de campo foram usadas em laboratório. Inicialmente, as folhas de C. tenella mostraram-se mais nutritivas e macias, enquanto que as de N. megapotamica foram mais duras e lignificadas. Os fragmentadores preferiram o detrito com menor dureza e condicionados pelos fungos (campo: C. tenella; laboratório: N. megapotamica, ambas condicionadas por 14 dias), ou seja, estes parecem ser os fatores determinantes para a escolha dos Phylloicus. Após 14 dias, as folhas de N. megapotamica apresentaram decréscimo na dureza, que está associado ao condicionamento microbiano, e que explicou o padrão de consumo por Phylloicus. Nós encontramos evidências em campo e em laboratório que os Phylloicus são seletivos em relação ao alimento e que as características foliares, especialmente relacionadas à estrutura da folha (ex. dureza foliar e lignina), determinam a associação e a preferência destes fragmentadores.(AU)

Shredders prefer soft and fungal-conditioned leaves, regardless of their initial chemical traits / Fragmentadores preferem folhas macias e condicionadas por fungos, independente da sua qualidade química inicial

Through field and laboratory experiments we investigated the effects of leaf traits of two tree species and microbial conditioning on the abundance, biomass, and feeding preference of a typical macroinvertebrate shredder. In the field, we compared the association of Phylloicus (Calamoceratidae, Trichoptera) with two tree species commonly found in riparian zones, which are representative of high and low nutritional quality, respectively: Nectandra megapotamica and Chusquea tenella. In the laboratory, we investigated the feeding preference of Phylloicus using unconditioned leaves and leaves conditioned by aquatic fungi. The same tree species used in the field experiment were used in the laboratory. Initially, C. tenella leaves were proved to be more nutritious and softer, while N. megapotamica leaves were harder and more lignified. The shredders preferred conditioned leaf detritus of reduced toughness (field: C. tenella; laboratory: N. megapotamica, both conditioned for 14 days). These leaf traits seem to be crucial for the choice process of Phylloicus. After 14 days, N. megapotamica leaves showed a decreased toughness associated with the microbial conditioning, which explained its consumption rate by Phylloicus. In both field and laboratory experiments, we found evidence that Phylloicus is a selective feeding shredder, and that the leaf traits, especially leaf structure (e.g., leaf toughness and lignin content), determine its association and preferences.

Nós investigamos em experimento de campo e de laboratório os efeitos das características foliares e condicionamento microbiano de duas espécies de árvores na abundância, biomassa e preferência alimentar de um fragmentador típico. No experimento de campo, comparamos a associação do Phylloicus (Calamoceratidae, Trichoptera) entre duas espécies vegetais, comumente encontradas em zonas ripárias, que são representativas de alta e baixa qualidade nutricional, respectivamente: Nectandra megapotamica e Chusquea tenella. Em experimento de laboratório, investigamos a preferência alimentar de Phylloicus, usando folhas condicionadas e não condicionadas pelos fungos aquáticos. As mesmas espécies vegetais usadas no experimento de campo foram usadas em laboratório. Inicialmente, as folhas de C. tenella mostraram-se mais nutritivas e macias, enquanto que as de N. megapotamica foram mais duras e lignificadas. Os fragmentadores preferiram o detrito com menor dureza e condicionados pelos fungos (campo: C. tenella; laboratório: N. megapotamica, ambas condicionadas por 14 dias), ou seja, estes parecem ser os fatores determinantes para a escolha dos Phylloicus. Após 14 dias, as folhas de N. megapotamica apresentaram decréscimo na dureza, que está associado ao condicionamento microbiano, e que explicou o padrão de consumo por Phylloicus. Nós encontramos evidências em campo e em laboratório que os Phylloicus são seletivos em relação ao alimento e que as características foliares, especialmente relacionadas à estrutura da folha (ex. dureza foliar e lignina), determinam a associação e a preferência destes fragmentadores.

Shredders prefer soft and fungal-conditioned leaves, regardless of their initial chemical traits

ABSTRACT Through field and laboratory experiments we investigated the effects of leaf traits of two tree species and microbial conditioning on the abundance, biomass, and feeding preference of a typical macroinvertebrate shredder. In the field, we compared the association of Phylloicus (Calamoceratidae, Trichoptera) with two tree species commonly found in riparian zones, which are representative of high and low nutritional quality, respectively: Nectandra megapotamica and Chusquea tenella. In the laboratory, we investigated the feeding preference of Phylloicus using unconditioned leaves and leaves conditioned by aquatic fungi. The same tree species used in the field experiment were used in the laboratory. Initially, C. tenella leaves were proved to be more nutritious and softer, while N. megapotamica leaves were harder and more lignified. The shredders preferred conditioned leaf detritus of reduced toughness (field: C. tenella; laboratory: N. megapotamica, both conditioned for 14 days). These leaf traits seem to be crucial for the choice process of Phylloicus. After 14 days, N. megapotamica leaves showed a decreased toughness associated with the microbial conditioning, which explained its consumption rate by Phylloicus. In both field and laboratory experiments, we found evidence that Phylloicus is a selective feeding shredder, and that the leaf traits, especially leaf structure (e.g., leaf toughness and lignin content), determine its association and preferences.

RESUMO Nós investigamos em experimento de campo e de laboratório os efeitos das características foliares e condicionamento microbiano de duas espécies de árvores na abundância, biomassa e preferência alimentar de um fragmentador típico. No experimento de campo, comparamos a associação do Phylloicus (Calamoceratidae, Trichoptera) entre duas espécies vegetais, comumente encontradas em zonas ripárias, que são representativas de alta e baixa qualidade nutricional, respectivamente: Nectandra megapotamica e Chusquea tenella. Em experimento de laboratório, investigamos a preferência alimentar de Phylloicus, usando folhas condicionadas e não condicionadas pelos fungos aquáticos. As mesmas espécies vegetais usadas no experimento de campo foram usadas em laboratório. Inicialmente, as folhas de C. tenella mostraram-se mais nutritivas e macias, enquanto que as de N. megapotamica foram mais duras e lignificadas. Os fragmentadores preferiram o detrito com menor dureza e condicionados pelos fungos (campo: C. tenella; laboratório: N. megapotamica, ambas condicionadas por 14 dias), ou seja, estes parecem ser os fatores determinantes para a escolha dos Phylloicus. Após 14 dias, as folhas de N. megapotamica apresentaram decréscimo na dureza, que está associado ao condicionamento microbiano, e que explicou o padrão de consumo por Phylloicus. Nós encontramos evidências em campo e em laboratório que os Phylloicus são seletivos em relação ao alimento e que as características foliares, especialmente relacionadas à estrutura da folha (ex. dureza foliar e lignina), determinam a associação e a preferência destes fragmentadores.

Conidial fungi associated with leaf litter of red cedar (Cedrela odorata) in Belém, Pará (eastern Brazilian Amazon) / Fungos conidiais associados com o folhedo de cedro vermelho (Cedrela odorata) em Belém, Pará (Amazônia Oriental brasileira)

The aim of this study was to investigate the species of conidial fungi associated with leaf litter of Cedrela odorata (Meliaceae), an endangered red cedar species typical of Amazonian terra-firme forests. Conidial fungi were sampled around C. odorata individuals in three forest areas in the municipality of Belém (Pará State, Brazil). A total of 104 species were identified, with 53 new records for the state of Pará, 46 first records for the Brazilian Amazon, including new records for Brazil (Cordana abramovii), for South America (Acarocybiopsis cubitaensis, Xylocladium claviforme) and for the Americas (Dactylaria biguttulata). A review of species of conidial fungi reported on C. odorata is provided, indicating its distribution in Brazil. For each new record in Brazil, South America and the Americas we present a description, illustrations, geographical distribution and taxonomic comments.(AU)

O objetivo deste estudo foi investigar as espécies de fungos conidiais associadas com o folhedo de Cedrela odorata, uma espécie de cedro vermelho ameaçada, típica de florestas de terra firme da Amazônia. Fungos conidiais foram amostrados no folhedo ao redor de indivíduos de C. odorata em três áreas florestais no município de Belém (PA). Um total de 104 espécies foi identificado, com 53 novos registros para o Estado do Pará e 46 que representam o primeiro registro para a Amazônia brasileira. Dentre estas, foram encontrados novos registros para o Brasil (Cordana abramovii), para a América do Sul (Acarocybiopsis cubitaensis, Xylocladium claviforme) e para as Américas (Dactylaria biguttulata). Uma revisão das espécies de fungos conidiais relatadas em C. odorata é fornecida, indicando sua distribuição no Brasil. Para cada novo registro no Brasil, América do Sul e Américas apresentamos uma descrição, ilustrações, distribuição geográfica e comentários taxonômicos.(AU)

Conidial fungi associated with leaf litter of red cedar (Cedrela odorata) in Belém, Pará (eastern Brazilian Amazon) / Fungos conidiais associados com o folhedo de cedro vermelho (Cedrela odorata) em Belém, Pará (Amazônia Oriental brasileira)

The aim of this study was to investigate the species of conidial fungi associated with leaf litter of Cedrela odorata (Meliaceae), an endangered red cedar species typical of Amazonian terra-firme forests. Conidial fungi were sampled around C. odorata individuals in three forest areas in the municipality of Belém (Pará State, Brazil). A total of 104 species were identified, with 53 new records for the state of Pará, 46 first records for the Brazilian Amazon, including new records for Brazil (Cordana abramovii), for South America (Acarocybiopsis cubitaensis, Xylocladium claviforme) and for the Americas (Dactylaria biguttulata). A review of species of conidial fungi reported on C. odorata is provided, indicating its distribution in Brazil. For each new record in Brazil, South America and the Americas we present a description, illustrations, geographical distribution and taxonomic comments.

O objetivo deste estudo foi investigar as espécies de fungos conidiais associadas com o folhedo de Cedrela odorata, uma espécie de cedro vermelho ameaçada, típica de florestas de terra firme da Amazônia. Fungos conidiais foram amostrados no folhedo ao redor de indivíduos de C. odorata em três áreas florestais no município de Belém (PA). Um total de 104 espécies foi identificado, com 53 novos registros para o Estado do Pará e 46 que representam o primeiro registro para a Amazônia brasileira. Dentre estas, foram encontrados novos registros para o Brasil (Cordana abramovii), para a América do Sul (Acarocybiopsis cubitaensis, Xylocladium claviforme) e para as Américas (Dactylaria biguttulata). Uma revisão das espécies de fungos conidiais relatadas em C. odorata é fornecida, indicando sua distribuição no Brasil. Para cada novo registro no Brasil, América do Sul e Américas apresentamos uma descrição, ilustrações, distribuição geográfica e comentários taxonômicos.

Combined Effects of Dissolved Nutrients and Oxygen on Plant Litter Decomposition and Associated Fungal Communities.

Aquatic ecosystems worldwide have been substantially altered by human activities, which often induce changes in multiple factors that can interact to produce complex effects. Here, we evaluated the combined effects of dissolved nutrients (nitrogen [N] and phosphorus [P]; three levels: concentration found in oligotrophic streams in the Cerrado biome, 10× and 100× enriched) and oxygen (O2; three levels: hypoxic [4% O2], depleted [55% O2], and saturated [96% O2]) on plant litter decomposition and associated fungal decomposers in laboratory microcosms simulating stream conditions under distinct scenarios of water quality deterioration. Senescent leaves of Maprounea guianensis were incubated for 10 days in an oligotrophic Cerrado stream to allow microbial colonization and subsequently incubated in microcosms for 21 days. Leaves lost 1.1-3.0% of their initial mass after 21 days, and this was not affected either by nutrients or oxygen levels. When considering simultaneous changes in nutrients and oxygen concentrations, simulating increased human pressure, fungal biomass accumulation, and sporulation rates were generally inhibited. Aquatic hyphomycete community structure was also affected by changes in nutrients and oxygen availability, with stronger effects found in hypoxic treatments than in depleted or saturated oxygen treatments. This study showed that the effects of simultaneous changes in the availability of dissolved nutrients and oxygen in aquatic environments can influence the activity and composition of fungal communities, although these effects were not translated into changes in litter decomposition rates.

MANEJO INTEGRADO DE LA MARCHITEZ VASCULAR DEL TOMATE [Fusarium oxysporum f. sp. lycopersici (SACC.) W.C. SNYDER & H.N. HANSEN]:: UNA REVISIÓN / INTEGRATED DISEASE MANAGEMENT OF FUSARIUM WILT OF TOMATO [Fusarium oxysporum f. sp. lycopersici (SACC.) W.C. SNYDER & H.N. HANSEN]:: A REVIEW

El tomate (Solanum lycopersicum L.) es una de las hortalizas más consumidas en el mundo y es atacada por numerosas enfermedades, entre las cuales, está la marchitez vascular, causada por Fusarium oxysporum f. sp. lycopersici. El patógeno, por ser habitante del suelo, es difícil de manejar. Una vez el suelo se infesta puede permanecer con el patógeno por tiempo indefinido. Debido al cultivo sucesivo de tomate en el mismo lugar, la población del hongo aumenta y, por ende, la incidencia de la enfermedad. Aún no se han establecido umbrales de daño económico ni sistemas de predicción, pero se conocen algunas condiciones del suelo, que pueden disminuir la incidencia de la enfermedad, como pH alto o una población alta de microorganismos antagonistas. Se han reportado numerosas prácticas de manejo enfocadas, especialmente hacia el suelo; sin embargo, son pocos los reportes acerca del manejo integrado de la enfermedad. Para la preparación de este documento, se revisó la literatura mundial y se analizó la naturaleza del patógeno, su ciclo de vida y diseminación, conocimiento primordial para realizar un manejo adecuado de la enfermedad; también las diferentes prácticas de manejo y, finalmente, la combinación de estas prácticas. El objetivo de esta revisión fue reunir la información más relevante generada en los últimos años, en torno al manejo integrado de F. oxysporum f. sp. lycopersici, enfocando cada práctica dentro del modelo logístico de Van der Plank, que permite darles una interpretación cuantitativa.

Tomato (Solanum lycopersicum L.) is one of the most consumed vegetables in the world and is attacked by numerous diseases, including the vascular wilt, caused by Fusarium oxysporum f. sp. lycopersici. The pathogen, being an inhabitant of the soil is difficult to manage. Once the soil is infested, it can remain with the pathogen indefinitely. Due to the successive cultivation of tomato in the same field the population of the fungus increases and, consequently, the incidence of the disease. No thresholds for economic damage or prediction systems have yet been established, but some soil conditions are known to reduce the incidence of the disease, such as high pH or a high population of antagonistic microorganisms. Numerous management practices have been reported, especially focused toward the soil; however, there are few articles on integrated management of the disease. For the preparation of this document, the world literature was reviewed and addressed the nature of the pathogen, its life cycle and dissemination, essentials to carry out an adequate management of the disease; also, the different management practices and finally the combination of these practices. The objective of this review was to gather the most relevant information generated in recent years on the integrated management of F. oxysporum f. sp. lycopersici, focusing each practice within the logistic model of Van der Plank, which allows giving to each one a quantitative interpretation.

Nutrient enrichment in water more than in leaves affects aquatic microbial litter processing.

Nutrient enrichment of soils and water will intensify in the future and has the potential to alter fundamental ecosystem processes, such as litter decomposition. We tested the direct (via water nutrient enrichment) and indirect (via changes in leaf chemistry) effects of nutrient enrichment on microbial activity and decomposability of Quercus robur L. (oak) leaves in laboratory microcosms simulating streams. Senescent leaves of oak trees grown without and with fertilization were incubated under ambient and elevated water nutrient [nitrogen (N) and phosphorus (P)] concentrations for 60 days. Soil fertilization led to an increase in leaf (3.4×) and leaf litter (2.3×) N concentration. Increased water-dissolved nutrients concentrations stimulated microbial activity (N uptake, microbial respiration, fungal biomass buildup and conidia production by aquatic hyphomycetes) that translated into accelerated litter decomposition (2.1× for unfertilized and 1.6× for fertilized trees). Leaves from fertilized trees had higher microbial activity and decomposition rates than leaves from unfertilized trees only at low dissolved nutrient availability. When both litter and water nutrients concentration increased, microbial activity and leaf decomposition were stimulated, but the effects were additive and direct effects from increased dissolved nutrient availability were stronger than those mediated by increases in litter N concentration (indirect effects). Our results suggest that increases in water nutrient availability (within the range used in this study) may exert a stronger control on microbial activity and litter decomposition than litter nutrient enrichment.

Passalora stromatica sp. nov. associated with leaf spots of Tithonia diversifolia in Brazil.

Tithonia diversifolia, a member of Compositae native to Central America that produces showy sunflower-like flowers, became an invasive weed in other continents after it was introduced as an ornamental. Little is known about fungal pathogens infecting this plant. Knowledge of its mycobiota is of interest for future biocontrol programmes for T. diversifolia. In Brazil, a cercosporoid hyphomycete was found associated with intense leaf-spotting of this plant. Based on morphological and molecular data it was recognized as representing a new species of Passalora, and the name Passalora stromatica sp.nov. is introduced here for this taxon. This fungus is described and illustrated herein. It is possible that this fungus is playing a role in Brazil in reducing the invasiveness of T. diversifolia as, contrarily to what has been reported for countries in Africa and Asia, it remains mostly as a garden escape or rural plant in Brazil.

Isolation of Papulaspora halima and a new morphological variety of Halosphaeria tubulifera from seawater of potter cove (King George Island, South Shetland Island, Antarctica) / Aislamiento de Papulaspora halima y de una nueva variedad morfológica de Halosphaeria tubulifera desde agua de mar de Potter Cove (Isla Rey Jorge /25 de Mayo, islas Shetland del Sur, Antártida)

Marine fungi ascribed to the ascomycetes and the hyphomycetes are infrequently reported for the Southern Ocean. For this reason, the main objective of the present work was to detect the presence of these fungi seawater of Potter Cove, King George (25 de Mayo) Island, South Shetland Island, Antarctica. For this purpose marine fungi were grown on wood test panels, placed into plastic nets in the tidal zone, exposed to the Antarctic seawater for different periods of time, which ranged between 2 and 12 months.As a result of this survey, we were able to recover and identify two marine fungi, Papulospora halima (which represents the first report for this environment) and a new morphological variety of Halosphaeria tubulifera.

Los ascomicetes e hifomicetes marinos están escasamente documentados para el océano Atlántico Sur. Por este motivo, el principal objetivo del presente trabajo fue detectar la presencia de dichos hongos en las agua marinas de la Potter Cove, en la isla Rey Jorge/25 de Mayo (islas Shetland del Sur, Antártida). Para este propósito, los hongos marinos se desarrollaron en paneles de madera dentro de una red plástica en la zona tidal, expuestos al agua de mar antártica por diferentes períodos de tiempo que oscilaron entre 2 a 12 meses. Como resultado de este estudio, fuimos capaces de recuperar e identificar 2 hongos marinos, Papulospora halima (que representa el primer reporte para este ambiente) y una nueva variedad morfológica de Halosphaeria tubulifera.

The diversity of aquatic Hyphomycetes in South America

Aquatic Hyphomycetes, also named Ingoldian or freshwater fungi, constitute a group of anamorphic fungi that are typically aquatic, producing tetraradiate, sigmoid or spherical conidia on submerged plant debris (leaf litter, petioles, bark, etc.). Mainly occurring in lotic systems, these fungi are considered to be one of the most active groups of organisms in the decomposition of leaf litter, and play a crucial role in the trophic chain. In South America, aquatic Hyphomycetes are mentioned for Argentina, Brazil, Chile, Ecuador, Peru and Venezuela, totalizing the report of about 90 species. Almost all studies are taxonomical, some with proper drawings and complete descriptions, but no keys have been provided yet, nor there is a specific culture collection for preserved strains. The published papers are still sporadic and dispersed, emphasizing a great need to improve the knowledge of the diversity of South American aquatic Hyphomycetes. The present review contents the check list of reported species until now, and has the aim to encourage the research concerned with aquatic Hyphomycetes in non explored regions of the continent.

Os Hyphomycetes aquáticos, também denominados fungos "Ingoldeanos", constituem grupo de fungos anamórficos tipicamente aquáticos, que produzem conídios tetrarradiados, sigmóides ou esféricos sobre substratos vegetais submersos (folhedo, pecíolos, cortiça, etc.). Ocorrendo principalmente em sistemas lóticos, estes fungos são considerados como um dos grupos de organismos mais ativos na decomposição de folhedo, assumindo papel crucial na cadeia trófica. Na América do Sul os Hyphomycetes aquáticos são mencionados para a Argentina, Brasil, Chile, Equador, Peru e Venezuela, totalizando a citação de aproximadamente 90 espécies. Quase todos os estudos são taxonômicos, com ilustrações adequadas e descrições completas, porém ainda não foram elaboradas chaves sistemáticas ou coleções de culturas de linhagens específicas. Os artigos publicados ainda são esporádicos e dispersos, enfatizando-se a grande necessidade de aperfeiçoamento dos conhecimentos sobre a diversidade dos Hyphomycetes aquáticos na América do Sul. A presente revisão contém listas das espécies mencionadas até o momento e tem o objetivo de encorajar a pesquisa destes fungos em áreas ainda não investigadas no continente.