''Carbonea austroshetlandica'' is a species of

lichenicolous fungus A lichenicolous fungus is a member of a specialised group of fungi that live exclusively on lichens as their host organisms. These fungi, comprising over 2,000 known species across 280 genera, exhibit a wide range of ecological strategies, includ ...

belonging to the family

Lecanoraceae The Lecanoraceae are a family of lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the c ...

. It was discovered in the

South Shetland Islands The South Shetland Islands are a group of List of Antarctic and subantarctic islands, Antarctic islands located in the Drake Passage with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the n ...

where it grows on '' Carbonea assentiens'' but has since been reported from King George Island where it uses ''

Rhizocarpon geographicum ''Rhizocarpon geographicum'' (the map lichen) is a species of lichen, which grows on rocks in mountainous areas of low air pollution. Each lichen is a flat patch bordered by a black line of fungal hyphae. These patches grow adjacent to each other ...

'' as a host.

Description

''Carbonea austroshetlandica'' has dispersed to aggregated

ascoma An ascocarp, or ascoma (: ascomata), 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. Ascoc ...

ta, which are up to 0.3 mm in diameter, abruptly becoming convex with excluded margin. Hypothecium and

exciple A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship.

are dark brown and the epihymenium is greenish. The

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 oth ...

hyaline A hyaline substance is one with a glassy appearance. The word is derived from , and . Histopathology Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...

, 35–48

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

high and stains blue with KI solution.

Paraphyses Paraphyses are erect sterile filament-like support structures occurring among the reproductive apparatuses of fungi, ferns, bryophytes and some thallophytes. The singular form of the word is paraphysis. In certain fungi, they are part of the f ...

are branched and anastomosing, slightly enlarged at the apex. Asci are broadly ellipsoid, 28–32 × 15–16 μm. Ascospores hyaline, ellipsoid, simple, 9–10 × 3.5–4.5 μm.

Ecology

''Carbonea austroshetlandica'' is a

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

saprobe Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

, unlike the similar '' Carbonea aggregantula'' which has a

symbiotic relationship Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

with its host.

References

Lecanoraceae Lichen species Lichens described in 2018 Lichens of the subantarctic islands {{Lecanorales-stub