In: Sydowia 71, (2019): 255-265, ISSN 0082-0598, DOI 10.12905/0380.sydowia71-2019-0255, Published online on January 13, 2020

Diversity and distribution of zoosporic fungi (Blastocladiomycota and Chytridiomycota) in three tropical reservoirs

Gustavo Henrique Jerônimo & Carmen Lidia Amorim Pires-Zottarelli

Jerônimo G. H. & Pires-Zottarelli C. L. A. (2019) Diversity and distribution of zoosporic fungi (Blastocladiomycota and Chytridiomycota) in three tropical reservoirs. – Sydowia 71: 255-265.

The zoosporic fungi of Blastocladiomycota and Chytridiomycota are important components of eukaryotic communities in
freshwater ecosystems, acting in decomposing of organic matter and/or parasitism of several hosts. In Brazil, these fungi in lentic
habitats such as reservoirs and lakes are still poorly studied, leaving the sediment totally unexplored. Thus, the aim of this study
was to analyze the diversity and distribution of these phyla in the water column and sediments of three tropical reservoirs located
in Brazilian Atlantic rainforest areas using morphological and phylogenetic approaches. Samples of the water column depths
(surface, medium depth and bottom) and sediment were collected from August/2014 to July/2015 (four samplings), and baited
with substrates to allow the fungal development. The taxa purified on agar medium were included in phylogenetic reconstructions
(SSU, ITS and/or LSU regions of rDNA) to corroborate their morphological identifications. In total, we identified 24 taxa and
calculated their frequency, occurrence and abundance during the study. Nine of them were isolated on pure cultures, which were
included in phylogenic reconstructions at order level. In general, the zoosporic fungi presented a higher species richness in the
sediment. Asterophlyctis sarcoptoides, Cladochytrium replicatum, Nowakowskiella crenulata and N. hemisphaerospora were the
taxa more frequent and abundant. The genus Avachytrium is recorded for the first time in Brazil. These data corroborate the
importance of the sediment to obtain a more comprehensive overview of the zoosporic fungi community in lentic ecosystems.

Keywords: chytrids, morphology, molecular phylogeny, sediment, water column