First reports of fimicolous myxomycetes (Protozoa: Amoebozoa) from Brazilian Cerrado and Pantanal biomes

Abstract

Fimicolous organisms are those that can grow on dung. These substrates offer conditions that favour colonization by microorganisms, such as high nutrient and moisture content and an alkaline-neutral pH that is especially advantageous in arid/desertic regions. There are about 250 species of myxomycetes known from Brazil, which are distributed in all geographic regions and biomes, obtained mainly from plant-derived substrates. However, there are some reports of fimicolous myxomycetes in Brazil. In this study, we expand this knowledge with new records of fimicolous myxomycetes in multiple Brazilian biomes. Between 2017 and 2018, horse and cattle dung samples were collected in municipal areas in the State of Goiás (Cerrado biome): Pirenópolis, Goiás, and Porangatu; and the State of Mato Grosso (Pantanal biome): Poconé. Samples were incubated in moist chambers and monitored for four months. Myxomycetous fructifications were observed, photographed under stereo and light microscopes, and morphologically identified. Vouchers were deposited at the HUEG Herbarium. A total of five species of myxomycetes were recorded: <em>Arcyria cinerea and <em>Physarum viride (Pirenópolis), <em>P. cinereum (Goiás City), <em>P. melleum</em> (Porangatu), and <em>Perichaena corticalis</em> (Poconé). They represent the first records of fimicolous myxomycetes from the Brazilian Cerrado and Pantanal biomes. Additionally, <em>P. melleum</em> was reported as fimicolous for the first time in Brazil and the second time in the world; <em>P. corticalis</em> was reported for the first time in midwest region as well as for the first time as fimicolous in Brazil; and <em>P. viride</em> was reported for the first time as fimicolous in the world.