Composition and Diversity of Fungal Decomposers of Submerged Wood in Two Lakes in the Brazilian Amazon State of Pará

Abstract

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. The 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 Pará). Fragments of decaying wood (30 samples per lake) were collected from the Lakes Juá and Maicá. The 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 Juá (10 sexual and 13 asexual) and 26 taxa in the Lake Maicá (17 sexual, 9 asexual). ITS sequences were obtained for 14 taxa to aid in identification. In the Lakes Juá and Maicá, the diversity indices were H': 2.6514 and H': 2.8174, respectively. The Sørensen index of the fungal communities in the studied lakes was 0.3673. This study is the first to describe the fungal biodiversity of two important aquatic environments in Pará, Brazil.