Research Article CompositionandDiversityofFungalDecomposersofSubmerged Wood in Two Lakes in the Brazilian Amazon State of Par´ a EveleiseSamiraMartinsCanto , 1,2 AnaCla´ udiaAlvesCortez, 3 JosianeSantanaMonteiro, 4 Flavia Rodrigues Barbosa, 5 Steven Zelski , 6 and João Vicente Braga de Souza 3 1 Programa de P´ os-Graduação da Rede de Biodiversidade e Biotecnologia da Amazˆ onia Legal-Bionorte, Manaus, Amazonas, Brazil 2 Universidade Federal do Oeste do Par´ a, UFOPA, Santar´ em, Par´ a, Brazil 3 Instituto Nacional de Pesquisas da Amazˆ onia, INPA, Laborat´ orio de Micologia, Manaus, Amazonas, Brazil 4 Museu Paraense Emilio Goeldi-MPEG, Bel´ em, Par´ a, Brazil 5 Universidade Federal de Mato Grosso, UFMT, Sinop, Mato Grosso, Brazil 6 Miami University, Department of Biological Sciences, Middletown, OH, USA Correspondence should be addressed to Eveleise Samira Martins Canto; eveleisesamira@hotmail.com and Steven Zelski; zelskise@miamioh.edu Received 25 August 2019; Revised 20 February 2020; Accepted 4 March 2020; Published 9 April 2020 Academic Editor: Giuseppe Comi Copyright © 2020 Eveleise Samira Martins Canto et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Aquatic ecosystems in tropical forests have a high diversity of microorganisms, including fungi, which are important decomposers of submerged wood. Despite the importance of their role in decomposition, research concerning the diversity of freshwater fungi from Brazilian Amazonian environments is scarce. e aim of this work was to describe the composition and diversity of fungi present on submerged wood in two lakes of the Brazilian Amazon (State of Par´ a). Fragments of decaying wood (30 samples per lake) were collected from the Lakes Ju´ a and Maic´ a. e wood samples were inspected for 6 months in the presence of fungal reproductive structures. Fungi observed in the wood were identified morphologically. Twenty-three taxa were identified in the Lake Ju´ a (10 sexual and 13 asexual) and 26 taxa in the Lake Maic´ a (17 sexual, 9 asexual). ITS sequences were obtained for 14 taxa to aid in identification. In the Lakes Ju´ a and Maic´ a, the diversity indices were H’: 2.6514 and H’: 2.8174, respectively. e Sørensen index of the fungal communities in the studied lakes was 0.3673. is study is the first to describe the fungal biodiversity of two important aquatic environments in Par´ a, Brazil. 1.Introduction Freshwater fungi include species that inhabit water for all or part of their life cycle or any species adapted to colonize predominantly aquatic or semiaquatic substrates in nature [1]. ese organisms serve as key agents in the decompo- sition of submerged dead plant material. Fungal biomass is a source of nutrition for other organisms in aquatic ecosys- tems [2, 3]. Fungal enzymatic activity also modifies plant substrates to make them more palatable to invertebrate shredders and scrapers [4]. Freshwater ascomycetes are a group of fungi known to actively participate in the decomposition of submerged woody debris [5, 6]. is group is polyphyletic, with the majority of species belonging to the subphylum Pezizo- mycotina in the classes Leotiomycetes, Sordariomycetes, and Dothideomycetes [2, 7]. Members of the Eurotiomycetes [8] and Orbiliomycetes [9] are less common. Shearer and Raja [10] reported that freshwater ascomycetes are distributed in relatively few orders: Helotiales, Pleosporales, Sordariales, Savoryellales, Microascales, Eurotiales, and Jahnulales. e number of known taxa has increased in recent years due to broader sampling and the use of molecular methods for identification [11, 12]. e Amazon basin is arguably the most complex net- work of aquatic habitats on the planet [13]. is vast region Hindawi International Journal of Microbiology Volume 2020, Article ID 6582514, 9 pages https://doi.org/10.1155/2020/6582514