Miracula einbuarlaekurica sp. nov., a new holocarpic endoparasitoid species from pennate freshwater diatoms in Iceland

• Published in: Mycology
• Main Authors: Anthony T. Buaya, Marco Thines
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2021
• Subjects: biotrophic parasites; diatoms; ectrogella; miracula; oomycetes; phylogeny; one new species; Biology (General); QH301-705.5; Microbiology; QR1-502; Iceland
• Online Access: https://doi.org/10.1080/21501203.2021.1980446; https://doaj.org/article/f8b75b3d6ddd4eb89ba4dcf9f6c22441

Holocarpic oomycetes infecting freshwater diatoms are obligate endobiotic parasites reported from a wide range of habitats. So far, the taxonomy of and phylogeny of most species remains unresolved, since most have not been reported throughout the past decades and sequence data are available for only the four species, Aphanomycopsis bacillariacearum, Diatomophthora gillii, Ectrogella bacillariacearum, and the recently-discovered species Miracula moenusica. In the current study, a new freshwater diatom parasite resembling Ectrogella bacillariacearum in the sense of Scherffel was discovered from pennate diatoms (Ulnaria acus, Ulnaria ulna) collected from the small stream Einbúalækur on Víkurskarð, North Iceland and investigated for its life cycle and phylogenetic placement. In contrast to the original description, Scherffel reports an achlya-like spore discharge for Ectrogella bacillariacearum. The phylogenetic reconstruction and morphological characterisation in this study revealed that Scherffel’s E. bacillariacearum is largely unrelated to the epitype of the species and is a member of the early-diverging genus Miracula. Consequently, the new species is described as M. einbuarlaekurica in the present study. This adds a second freshwater member to the genus, demonstrating the high ecological adaptability of the genus, which thrives in both freshwater and marine ecosystems.