Chytridiomycota

Abstract

The Chytridiomycota is a phylum in the kingdom Fungi, whose members produce unwalled, asexual spores that swim by means of a single, posteriorly directed flagellum. Members are microscopic saprobes or parasites found in fresh and saline water and soils. The phylum contains two classes, the Monoblepharidomycetes with one order and the Chytridiomycetes with seven orders and several undescribed groups. Orders are based on molecular and ultrastructural characters. Many species of chytrids were described without these characters and need to be re‐examined to place them in the proper orders and genera. Chytrids are important as degraders of cellulose, keratin and chitin and also as algal pathogens, sometimes controlling algal blooms. A few are plant pathogens with Synchytrium endobioticum causing black wart of potatoes. The rhizophydialean chytrid Batrachochytrium dendrobatidis grows in keratinised skin cells of amphibians and is pathogenic to many species, causing amphibian population declines on several continents and extirpation of some species. Key Concepts: Members of the Chytridiomycota are ubiquitous in aquatic and terrestrial habitats and can be found by microscopically examining baits placed with aquatic debris or with soil plus water. Chytridiomycota reproduce primarily by zoospores, which are mitotically produced, contained by a membrane and motile via a posteriorly directed flagellum. Because of convergent evolution of light microscopic characters, many genera described before the molecular era are polyphyletic and may not be placed in the correct order. Systematics in the Chytridiomycota relies on transmission electron microscopic features of zoospores and on DNA sequence information. Algal parasites are usually species specific and are capable of affecting population levels of planktonic algae. Batrachochytrium dendrobatidis is a chytrid pathogen of amphibians responsible for some amphibian population declines on at least five continents.

Measuring night sky brightness: methods and challenges

“…The last decade has seen a rapid increase in research into artificial light in the nighttime environment (Table 1). This increased attention can be attributed to several factors, including: recognition of the impacts of artificial light on ecology and health [1,2,3], increasing amounts of artificial light in the environment [4,5], improved quality of imagery from space [6,7], the current global change in lighting technology [8], and increasing quality, ease, instruments, and methods for measuring light at starlight intensities [9,10].…”

“…While the increase in possible ways to measure artificial light is a positive development, it likely presents a barrier to newcomers to the field of light measurement. Furthermore, both the various terms and units used in standard and Table 1: Bi-yearly citations counts to the seminal "World Atlas" paper by Cinzano et al [11] (WA), the "Ecological Light Pollution" paper by Longcore & Rich [1] (LR), or references to "Sky Quality Meter" (SQM) in Google Scholar, [2005][2006][2007][2008][2009][2010][2011][2012][2013][2014][2015][2016] astronomical photometry and the typical amounts of light experienced in the environment are not familiar to most scientists. This presents a challenge for interdisciplinary researchers, such as biologists who wish to measure the light exposure during a field experiment (see the discussion in [12] and examples of such studies [13,14]).…”

Community composition of arctic root-associated fungi mirrors host plant phylogeny

“… 2015 ). Members of the Chytridiomycota are mainly known as decomposers, and a few are known to act as plant pathogens (Longcore and Simmons 2012 ). Still, this phylum probably consists of a high diversity of unknown species with unknown functions.…”

Fungi of entomopathogenic potential in Chytridiomycota and Blastocladiomycota, and in fungal allies of the Oomycota and Microsporidia

“…The Blastocladiomycota contains only the order Blastocladiales; this group contains zoospore-producing true fungi, with well-developed hyphae, closed mitosis, cell walls with β-1-3-glucan, and a secretory vesicle complex known as the Spitzenkörper (James et al 2020;Roberson 2020). Several of these were once model organisms (e.g., Allomyces and Blastocladiella; (Cantino et al 1968;Burke et al 1972), and obligate parasites of plants and animals (Longcore and Simmons 2012). They are divided into five families (Barr 2001): Blastocladiaceae which contains only saprobic species; Catenariaceae with both saprobes and pathogens; Coelomomycetaceae with pathogens of invertebrates; Physodermataceae with obligate parasites of plants; and Sorochytriaceae which contains a pathogen infecting tardigrades.…”