''Thelebolus'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
in the
Thelebolaceae family. Often considered related to
Pezizales
The Pezizales are an order of the subphylum Pezizomycotina within the phylum Ascomycota. The order contains 16 families, 199 genera, and 1683 species. It contains a number of species of economic importance, such as morels, the black and white tr ...
, 18S phylogenies show Thelebolales are a
sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
to
Pseudeurotiaceae and
Leotiales
The Leotiales are an order of ascomycete fungi. The order contains 2 families (the Bulgariaceae and the Leotiaceae), 11 genera, and 41 species
In biology, a species is the basic unit of classification and a taxonomic rank of an organ ...
.
ITS is an adequate
DNA barcode
DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The premise of DNA barcoding is that by comparison with a reference library of such DNA sections (also called " sequences"), an indi ...
but there are only six variable sites in ''Thelebolus''; β-tubulin is a recommended secondary barcode.
Their
ascomata
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mos ...
are < 500 ųm diam. and are usually considered apothecia.
Cleistothecium
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are ...
-like or
perithecium
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...
-like variants occur, but all have asci arranged in a
hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...
. Most species have eight ellipsoidal
ascospores
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or ...
in a club-shaped
ascus
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...
, but some ''Thelebolus'' asci have hundreds of ascospores. Ascospores are forcibly ejected synchronously in a sticky mass. Agar colonies are smooth and pinkish,
conidium
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...
producing collars ("phialides") arising directly on hyphae, and slimy, 1-celled, hyaline conidia that appear
yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...
-like. Ascoma production is favored by media such as carrot agar.
Most species grow on dung or are isolated from soil. Most are
psychrophiles
Psychrophiles or cryophiles (adj. ''psychrophilic'' or ''cryophilic'') are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from to . They have an optimal growth temperature at . They are found in ...
with optimal growth at 10–15°C and occur mostly in (sub)arctic ecosystems. They may have evolved in response to the double challenge of extreme cold while growing on dung, and the need to survive passage through the gut of warm-blooded animals.
''Thelebolus stercoreus'' is a cosmopolitan psychrophile on dung and in soil, with pale yellow to brown cleistothecia containing asci with 32–2000 ellipsoidal ascospores. Variants with different ascospore numbers often were considered different species, but phylogenetic studies do not support this. In the Antarctic, ''T. stercoreus'' grows in microalgal mats in lakes, perhaps associated with seabird dung.
References
External links
Index Fungorum
{{Taxonbar, from=Q7781007
Leotiomycetes