Aquatic hyphomycetes associated with plant debris in aquatic ecosystems of Rio Grande do Norte, Brazil
biodiversity, Dikarya, aquatic fungi, microfungi, tropical
Aquatic hyphomycetes constitute the asexual stage of ascomycetes and basidiomycetes that complete one or more phases of their life cycle in water. These fungi act in the decomposition of submerged plant debris, making the dissolved organic matter more palatable and with greater nutritional value for consumption by other decomposers. In Brazil, the first records were known in the Atlantic Forest of São Paulo in 1989. For the Northeast, scarce records are reported in the biome in Pernambuco and Rio Grande do Norte. The present study aimed to carry out an inventory and ecological analysis of these fungi associated with submerged plant debris of streams and lakes in Rio Grande do Norte. The collections of submerged debris (leaves and twigs) and water parameters were carried out in the water bodies of the Pium and Jiqui streams (Parnamirim-RN), and the lakes of Jiqui (Parnamirim-RN) and Ilhota (Nísia Floresta-RN) from June 2021 to April 2022. Wet chamber and submerged incubation methodologies were applied. Additionally, an inventory of previously isolated taxa was carried out from the streams Boa Cica (Nísia Floresta), Baldum (Georgino Avelino-RN), Catu (Canguaretama-RN), Espinho (Canguaretama-RN), Pedra (Baía Formosa-RN) and Guajú (Formosa Bay-RN). Seventy-six taxa were found, distributed in 35 genera of aquatic hyphomycetes associated with plant debris in water bodies of the Atlantic Forest of Rio Grande do Norte. Among the identified species, Flagellospora minuta is a new record for the Americas; Gyrothrix citricola and Triscelophorus konajensis for Brazil; F. stricta, Polylobatispora deltoidea, Pseudoxylomyces elegans and Spirosphaera carici-graminis are new records for the Brazilian Atlantic Forest; and 13 are new records for Rio Grande do Norte. The study demonstrated a high richness of aquatic hyphomycetes for the Atlantic Forest of Rio Grande do Norte and can support conservation studies in these areas.