Colony of Lepidopterella palustris on Malt extract agar.
Image Courtesy: Pedro Crous, CBS

Transitions from terrestrial to freshwater habitats have occurred several times independently in Dothideomycetes. Interestingly, recurrent shifts to aquatic lifestyles occur in Pleosporomycetidae but not in Dothideomycetidae. Lepidopterella palustris is a singleton freshwater lineage, which is sister to the Mytilinidiales with low bootstrap support (Shearer et al. 2009). This species colonizes submerged wooden debris in cypress swamps and rarely produces ascomata that show the characteristic papilionaceous (butterfly shaped) ascospores (Shearer and Crane 1980). Freshwater Ascomycetes are known to be key players in the decomposition of plant materials, however, recycling carbon sources in aquatic habitats using extracellular enzymes is a poorly understood process. The genome of Lepidopterella palustris will contribute to our knowledge of the enzymes involved that are essential in aquatic wood decay.

References
Shearer C.A. & Crane J.L. (1980). Taxonomy of two cleistothecial Ascomycetes with papilionaceous ascospores. Trans. Br. Mycol. Soc. 75: 193 – 200.

Shearer C.A., Raja H.A., Miller A.N., Nelson P., Tanaka K., Hirayama K., Marvanova L., Hyde K.D. & Zhang Y. (2009). The molecular phylogeny of freshwater Dothideomycetes. Studies in Mycology 64: 145 – 153.