Morphological and phylogenetic analyses of Gonatobotryum (Dothideaceae, Dothideales), and the description of a new species from a mangrove sediment in Brazil.

Gonatobotryum is an anamorphic fungus reported mainly as a saprophyte, parasite, or endophyte. The genus has traditionally been identified based on morphological features, with its phylogenetic placement remaining uncertain due to the lack of molecular data. During the analysis of fungi obtained from mangrove sediments in Brazil, nine isolates were morphologically identified as Gonatobotryum and subsequently analysed using the internal transcribed spacer (ITS) region, including the intervening 5.8S nRNA gene and the nuclear ribosomal RNA large subunit (LSU) gene, leading to the description of a new species, Gonatobotryum mangrovei. Additionally, the type material of Gonatobotryum bahiense was re-evaluated regarding its phylogenetic placement. Here, we propose a new combination, Ophiostoma bahiense, to place this species within the genus. Our results clarify the phylogenetic position of Gonatobotryum and expand the current understanding of fungi in mangrove environments.