species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
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 ...
that live in
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
* Marine habitats
* Marine life
* Marine pollution
Military
* ...
or
estuarine
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...
environments. They are not a
taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
group, but share a common habitat. Obligate marine fungi grow exclusively in the
marine habitat
Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmental a ...
while wholly or sporadically submerged in sea water. Facultative marine fungi normally occupy terrestrial or freshwater habitats, but are capable of living or even
sporulating
In biology, a spore is a unit of sexual reproduction, sexual or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of ...
in a marine habitat. About 444 species of marine fungi have been described, including seven genera and ten species of
basidiomycetes
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...
, and 177 genera and 360 species of
ascomycetes
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ...
. The remainder of the marine fungi are
chytrid
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrid ...
s and
mitosporic
The fungi imperfecti or imperfect fungi, are fungi which do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures because thei ...
or asexual fungi.Species of Higher Marine Fungi University of Mississippi. Retrieved 2012-02-05. Many species of marine fungi are known only from
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s and it is likely a large number of species have yet to be discovered. In fact, it is thought that less than 1% of all marine fungal species have been described, due to difficulty in targeting marine fungal DNA and difficulties that arise in attempting to grow cultures of marine fungi. It is impracticable to culture many of these fungi, but their nature can be investigated by examining seawater samples and undertaking rDNA analysis of the fungal material found.
Different marine habitats support very different fungal communities. Fungi can be found in niches ranging from ocean depths and coastal waters to
mangrove swamp
Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, are productive wetlands that occur in coastal intertidal zones. Mangrove forests grow mainly at tropical and subtropical latitudes because mangroves cannot withstand fre ...
s and estuaries with low salinity levels. Marine fungi can be
saprobic
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 (f ...
or
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...
on animals, saprobic or parasitic on
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
, saprobic on plants or saprobic on dead wood.
Overview
Terrestrial fungi play critical roles in nutrient cycling and food webs and can shape macroorganism communities as parasites and mutualists. Although estimates for the number of fungal species on the planet range from 1.5 to over 5 million, likely fewer than 10% of fungi have been identified so far. To date, a relatively small percentage of described species are associated with marine environments, with ∼1,100 species retrieved exclusively from the marine environment. Nevertheless, fungi have been found in nearly every marine habitat explored, from the surface of the ocean to kilometers below ocean sediments. Fungi are hypothesized to contribute to phytoplankton population cycles and the biological carbon pump and are active in the chemistry of
marine sediment
Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles have their origins in soil and rocks and have been transported from the land to the sea, mainly ...
s. Many fungi have been identified as commensals or pathogens of marine animals (e.g., corals and sponges), plants, and algae. Despite their varied roles, remarkably little is known about the diversity of this major branch of eukaryotic life in marine ecosystems or their ecological functions.Amend, A., Burgaud, G., Cunliffe, M., Edgcomb, V.P., Ettinger, C.L., Gutiérrez, M.H., Heitman, J., Hom, E.F., Ianiri, G., Jones, A.C. and Kagami, M. (2019 "Fungi in the marine environment: Open questions and unsolved problems" ''MBio'', 10(2): e01189-18. . Modified text was copied from this source, which is available under Creative Commons Attribution 4.0 International License
Fungi represent a large and diverse group of microorganisms in microbiological communities in the marine environment and have an important role in nutrient cycling. They are divided into two major groups;
obligate {{wiktionary, obligate
As an adjective, obligate means "by necessity" (antonym ''facultative'') and is used mainly in biology in phrases such as:
* Obligate aerobe, an organism that cannot survive without oxygen
* Obligate anaerobe, an organism that ...
marine fungi and
facultative
{{wiktionary, facultative
Facultative means "optional" or "discretionary" (antonym '' obligate''), used mainly in biology in phrases such as:
* Facultative (FAC), facultative wetland (FACW), or facultative upland (FACU): wetland indicator statuses ...
marine fungi.Raghukumar, S. The marine environment and the role of fungi. In Fungi in Coastal and Oceanic Marine Ecosystems: Marine Fungi; Springer International Publishing: Cham, Switzerland, 2017; pp. 17–38. Obligate marine fungi are adapted to reproduce in the aquatic environment, while facultative marine fungi can grow in aquatic as well as terrestrial environments. Marine fungi are called marine-derived fungi when their facultative or obligate state is not certain.Patyshakuliyeva, A., Falkoski, D.L., Wiebenga, A., Timmermans, K. and De Vries, R.P. (2020) "Macroalgae derived fungi have high abilities to degrade algal polymers". ''Microorganisms'', 8(1): 52. . Modified text was copied from this source, which is available under Creative Commons Attribution 4.0 International License
Marine fungal species occur as
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 ( ...
s,
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
s, or
symbiont
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
s and colonize a wide range of substrates, such as
sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...
s,
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...
s,
mangrove
A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...
s,
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...
es and
alga
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mi ...
e.
Factors that influence whether or not marine fungi are present in any particular location include the water temperature, its
salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
, the water movement, the presence of suitable substrates for colonization, the presence of propagules in the water, interspecific competition, pollution and the oxygen content of the water.
Some marine fungi which have ventured into the sea from terrestrial habitats include species that burrow into sand grains, living in the pores. Others live inside stony corals, and may become pathogenic if the coral is stressed by rising sea temperatures.
In 2011 the
phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...
of marine fungi was elucidated by analysis of their
small subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex.
Large assemblies of proteins such as viruses often use a small number of ty ...
ribosomal DNA
Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. These sequences regulate transcription initiation and amplification, and contain both transcribed and non-transcribed spacer segments.
In the human genome there are 5 chromos ...
sequences. Thirty six new marine lineages were found, the majority of which were
chytrids
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrids ...
but also some filamentous and multicellular fungi. The majority of the species found were
ascomycetous
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The de ...
and basidiomycetous yeasts.
The secondary metabolites produced by marine fungi have high potential for use in
biotechnological
Biotechnology is the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services. The term ''biotechnology'' was first used by ...
, medical and industrial applications.
Evolution
In contrast to
plants
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
and
animals
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
, the early fossil record of the fungi is meager. Since fungi do not biomineralise, they do not readily enter the fossil record. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
fungi.
The earliest fossils possessing features typical of fungi date to the
Paleoproterozoic
The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions (eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's ...
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...
organisms had filamentous structures capable of
anastomosis
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection m ...
, in which hyphal branches recombine. Other recent studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups.
For much of the
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant
Chytrid
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrid ...
s in having flagellum-bearing
spores
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
.
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
analyses suggest that the flagellum was lost early in the evolutionary history of the fungi, and consequently, the majority of fungal species lack a flagellum.
Evidence from DNA analysis suggests that all fungi are descended from one common ancestor, at least 600 million years ago. It is probable that these earliest fungi lived in water, and had
flagella
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates.
A microorganism may have f ...
. Fungi moved to land at about the same time as plants, about 460 million years ago, at least. Although fungi are
opisthokont
The opisthokonts () are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and ...
s—a grouping of evolutionarily related organisms broadly characterized by a single posterior
flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates.
A microorganism may have f ...
—all phyla except for the
chytrids
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrids ...
have lost their posterior flagella.
The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including
parasitism
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
mycorrhiza
A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant ...
and lichenization. Recent (2009) studies suggest that the ancestral ecological state of the
Ascomycota
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...
was saprobism, and that independent
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.hyphae
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high
surface area to volume ratio
The surface-area-to-volume ratio, also called the surface-to-volume ratio and variously denoted sa/vol or SA:V, is the amount of surface area per unit volume of an object or collection of objects.
SA:V is an important concept in science and engi ...
s. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many
plant pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...
s, including ''
Magnaporthe grisea
''Magnaporthe grisea'', also known as rice blast fungus, rice rotten neck, rice seedling blight, blast of rice, oval leaf spot of graminea, pitting disease, ryegrass blast, Johnson spot, neck blast, wheat blast, and Imochi (Japanese:稲熱) is a ...
'', form a structure called an
appressorium
An appressorium is a specialized cell typical of many fungal plant pathogens that is used to infect host plants. It is a flattened, hyphal "pressing" organ, from which a minute infection peg grows and enters the host, using turgor pressure capable ...
that evolved to puncture plant tissues. The pressure generated by the appressorium, directed against the plant
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
, can exceed . The filamentous fungus ''
Paecilomyces lilacinus
''Purpureocillium lilacinum'' is a species of filamentous fungus in the family Ophiocordycipitaceae. It has been isolated from a wide range of habitats, including cultivated and uncultivated soils, forests, grassland, deserts, estuarine sediments ...
'' uses a similar structure to penetrate the eggs of
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
s.
Fungi were considered to be part of the
plant kingdom
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude ...
until the mid-20th century. By the middle of the 20th century Fungi were considered a distinct kingdom, and the newly recognized kingdom
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 ...
becoming the third major kingdom of multicellular
eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...
s with kingdom
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
ae and kingdom
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
ia, the distinguishing feature between these kingdoms being the way they obtain nutrition.
Marine plants
Mangroves
The greatest number of known species of marine fungi are from
mangrove swamp
Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, are productive wetlands that occur in coastal intertidal zones. Mangrove forests grow mainly at tropical and subtropical latitudes because mangroves cannot withstand fre ...
s. In one study, blocks of
mangrove
A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...
wood and pieces of
driftwood
__NOTOC__
Driftwood is wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves.
In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and fo ...
of ''
Avicennia alba
''Avicennia alba'' is a species of tropical mangrove in the family Acanthaceae. It is found growing in coastal and estuarine locations in India, Southeast Asia, Australia, and Oceania.
Description
''A. alba'' forms a low, dense bushy crown ofte ...
'', ''
Bruguiera cylindrica
''Bruguiera cylindrica'' is a mangrove in the family Rhizophoraceae. It grows in mangrove swamps in tropical Asia.
Description
''Bruguiera cylindrica'' is a small tree growing up to tall but often grows as a bush. The bark is smooth and grey, ...
'' and ''
Rhizophora apiculata
Rhizophora apiculata (''R. apiculata'') belongs to the Plantae kingdom under the Rhizophoraceae family. Currently ''R. apiculata'' is distributed throughout Australia (Queensland and Northern Territory), Guam, India, Indonesia, Malaysia, Micrones ...
'' were examined to identify the
lignicolous
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...
(wood-decaying) fungi they hosted. Also tested were ''
Nypa fruticans
''Nypa fruticans'', commonly known as the nipa palm (or simply nipa, from ms, nipah) or mangrove palm, is a species of palm native to the coastlines and estuarine habitats of the Indian and Pacific Oceans. It is the only palm considered adapte ...
'', a mangrove palm and ''
Acanthus ilicifolius
''Acanthus ilicifolius'', commonly known as holly-leaved acanthus, sea holly, and holy mangrove is a species of shrubs or herbs, of the plant family Acanthaceae, native to Australia, Australasia, and Southeast Asia. It is used as medicine in asth ...
'', a plant often associated with mangroves. Each material was found to have its own characteristic fungi, the greatest diversity being among those growing on the mangrove palm. It was surmised that this was because the salinity was lower in the estuaries and creeks where ''Nypa'' grew, and so it required a lesser degree of adaptation for the fungi to flourish there. Some of these species were closely related to fungi on terrestrial palms. Other studies have shown that driftwood hosts more species of fungus than do exposed test blocks of wood of a similar kind. The mangrove leaf litter also supported a large fungal community which was different from that on the wood and living material. However, few of these were multicellular, higher marine fungi.
Other plants
The
sea snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
''
Littoraria irrorata
''Littoraria irrorata'', also known by the common name the marsh periwinkle, is a species of sea snail, a marine gastropod mollusk in the family Littorinidae. The specific epithet ' means 'moistened' or 'dewy.'
This species occurs in salt marshe ...
'' damages plants of ''
Spartina
''Spartina'' is a taxon of plants in the grass family, frequently found in coastal salt marshes. Its species are commonly known as cordgrass or cord-grass, and are native to the coasts of the Atlantic Ocean in western and southern Europe, north ...
'' in the coastal sea marshes where it lives, which enables spores of intertidal ascomycetous fungi to colonise the plant. The snail eats the fungal growth in preference to the grass itself. This mutualism between the snail and the fungus is considered to be the first example of husbandry among invertebrate animals outside the class
Insecta
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs o ...
.
Eelgrass, ''
Zostera marina
''Zostera marina'' is a flowering vascular plant species as one of many kinds of seagrass, with this species known primarily by the English name of eelgrass with seawrack much less used, and refers to the plant after breaking loose from the submer ...
'', is sometimes affected by
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...
wasting disease. The primary cause of this seems to be pathogenic strains of the
protist
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...
''
Labyrinthula zosterae
The genus ''Labyrinthula'' is part of the protist group Labyrinthulomycetes and contains thirteen species. The major feature of this genus is the formation of an ectoplasmic net secreted by specialized organelles called bothrosomes which surrou ...
'', but it is thought that fungal
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
s also contribute and may predispose the eelgrass to disease.
Wood
Many marine fungi are very specific as to which species of floating and submerged wood they colonise. A range of species of fungi colonise
beech
Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...
, while
oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
supports a different community. When a fungal propagule lands on a suitable piece of wood, it will grow if no other fungi are present. If the wood is already colonised by another fungal species, growth will depend on whether that fungus produces antifungal chemicals and whether the new arrival can resist them. The chemical properties of colonizing fungi also affect the animal communities that graze on them: in one study, when hyphae from five different species of marine fungi were fed to
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
s, one species supported less than half the number of nematodes per mg of hyphae than did the others.
Detection of fungi in wood may involve incubation at a suitable temperature in a suitable water medium for a period of six months to upward of eighteen months.
Lichens
Lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.mutualistic associations between
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 ...
, usually an ascomycete with a basidiomycete, and an alga or a
cyanobacterium
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue ...
. Several lichens, including ''
Arthopyrenia halodytes
''Arthopyrenia'' is a genus of fungi within the Arthopyreniaceae family. The genus has a widespread distribution, a cosmopolitan distribution. It formerly (in 2008) contained about 117 species.
Species
As accepted by Species Fungorum, (note ou ...
Lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Doushantuo Formation
The Doushantuo Formation (formerly transcribed as Toushantuo or Toushantou, from ) is a geological formation in western Hubei, eastern Guizhou, southern Shaanxi, central Jiangxi, and other localities in China. It is known for the fossil Lagerst ...
in China dating back about 600 million years ago.
Fungi from
Verrucariales
Verrucariales is an order of ascomycetous fungi within the subclass Chaetothyriomycetidae of the class Eurotiomycetes. Although most of the Verrucariales are lichenised, the family Sarcopyreniaceae consists of 11 species of lichenicolous (liche ...
also form marine lichens with the
brown algae
Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and po ...
''Petroderma maculiforme'', and have a symbiotic relationship with
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
Blidingia minima
''Blidingia minima'' is a species of seaweed in the Kornmanniaceae family. It was described by Johann Kylin in 1947.
Description
The species is long by wide and is light green in colour. It fronds are tubular with it cell arrangement being i ...
'', where the algae are the dominant components. The fungi is thought to help the rockweeds to resist desiccation when exposed to air. In addition, lichens can also use
yellow-green algae
Yellow-green algae or the Xanthophyceae (xanthophytes) are an important group of heterokont algae. Most live in fresh water, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamento ...
(''
Heterococcus
''Heterococcus'' is a genus of yellow-green algae
Yellow-green algae or the Xanthophyceae (xanthophytes) are an important group of heterokont algae. Most live in fresh water, but some are found in marine and soil habitats. They vary from singl ...
'') as their symbiotic partner.
Lichen-like fossils consisting of coccoid cells (
cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...
?) and thin filaments (mucoromycotinan
Glomeromycota
Glomeromycota (often referred to as glomeromycetes, as they include only one class, Glomeromycetes) are one of eight currently recognized divisions within the kingdom Fungi,
with approximately 230 described species. Members of the Glomeromycot ...
?) are permineralized in marine
phosphorite
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxi ...
of the
Doushantuo Formation
The Doushantuo Formation (formerly transcribed as Toushantuo or Toushantou, from ) is a geological formation in western Hubei, eastern Guizhou, southern Shaanxi, central Jiangxi, and other localities in China. It is known for the fossil Lagerst ...
in southern China. These fossils are thought to be 551 to 635 million years old or
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...
. Ediacaran
acritarchs
Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups. Their diversity refle ...
also have many similarities with
Glomeromycota
Glomeromycota (often referred to as glomeromycetes, as they include only one class, Glomeromycetes) are one of eight currently recognized divisions within the kingdom Fungi,
with approximately 230 described species. Members of the Glomeromycot ...
n vesicles and spores. It has also been claimed that Ediacaran fossils including ''
Dickinsonia
''Dickinsonia'' is an extinct genus of basal animal that lived during the late Ediacaran period in what is now Australia, China, Russia and Ukraine. The individual ''Dickinsonia'' typically resembles a bilaterally symmetrical ribbed oval. Its a ...
'', were lichens, although this claim is controversial. Endosymbiotic
Glomeromycota
Glomeromycota (often referred to as glomeromycetes, as they include only one class, Glomeromycetes) are one of eight currently recognized divisions within the kingdom Fungi,
with approximately 230 described species. Members of the Glomeromycot ...
comparable with living ''
Geosiphon
''Geosiphon'' is a genus of fungus in the family Geosiphonaceae. The genus is monotypic, containing the single species ''Geosiphon pyriformis'', first described by Kützing in 1849 as ''Botrydium pyriforme''. In 1915, Von Wettstein characterized ...
'' may extend back into the
Proterozoic
The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided ...
in the form of 1500 million year old ''
Horodyskia
''Horodyskia'' is a fossilised organism found in rocks dated from to . Its shape has been described as a "string of beads" connected by a very fine thread. It is considered one of the oldest known eukaryotes.
Biology
Comparisons of differe ...
'' and 2200 million year old ''
Diskagma
''Diskagma'' ("disc-like fragment") is a genus of problematic fossil from a Paleoproterozoic (2200 million years old) paleosol from South Africa, and significant as the oldest likely eukaryote and earliest evidence for megascopic life on land.
...
''. Discovery of these fossils suggest that marine fungi developed symbiotic partnerships with photoautotrophs long before the evolution of vascular plants.
Algae and phytoplankton
Marine fungi associated with algae are largely unexplored, despite their ecological role and potential industrial applications. For example, it has been shown that fungi associated with algae produce many bioactive
secondary metabolite
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...
s. Algae derived fungi can be associated with a variety of algae, including
brown
Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model used ...
Fucus
''Fucus'' is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.
Description and life cycle
The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. The erect portion o ...
'' sp., ''
Laminaria
''Laminaria'' is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relativ ...
'' sp., ''
Sargassum
''Sargassum'' is a genus of brown (class Phaeophyceae) macroalgae (seaweed) in the order Fucales. Numerous species are distributed throughout the temperate and tropical oceans of the world, where they generally inhabit shallow water and coral re ...
'' sp.),
green
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...
(e.g., ''
Ulva
Ulva (; gd, Ulbha) is a small island in the Inner Hebrides of Scotland, off the west coast of Mull. It is separated from Mull by a narrow strait, and connected to the neighbouring island of Gometra by a bridge. Much of the island is formed from ...
'' sp., ''
Enteromorpha
The sea lettuces comprise the genus ''Ulva'', a group of edible green algae that is widely distributed along the coasts of the world's oceans. The type species within the genus ''Ulva'' is ''Ulva lactuca'', ''lactuca'' being Latin for "lettuce ...
red
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...
(e.g. ''
Chondrus
''Chondrus'' is a genus of red algae containing 11 accepted species:
*''Chondrus armatus'' (Harvey) Okamura
*'' Chondrus canaliculatus'' (C.Agardh) Greville
*''Chondrus crispus'' Stackhouse
*''Chondrus elatus
''Chondrus'' is a genus of red a ...
'' sp., '' Dilsea'' sp., '' Ceramium'' sp.) algae.Kohlmeyer, J.; Volkmann-Kohlmeyer, B. Illustrated key to the filamentous higher marine fungi. Bot. Mar. 1991, 34, 1–61.Zuccaro, A.; Schoch, C.L.; Spatafora, J.W.; Kohlmeyer, J.; Draeger, S.; Mitchell, J.I. Detection and identification of fungi intimately associated with the brown seaweed Fucus serratus. Appl. Environ. Microbiol. 2008, 74, 931–941.Lee, S.; Park, M.S.; Lee, H.; Kim, J.J.; Eimes, J.A.; Lim, Y.W. Fungal diversity and enzyme activity associated with the macroalgae, Agarum clathratum. Mycobiology 2019, 47, 50–58.
Almost one-third of all known marine fungal species are associated with algae. The most commonly described fungi associated with algae belong to the
Ascomycota
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...
and are represented by a wide diversity of genera such as ''
Acremonium
''Acremonium'' is a genus of fungi in the family Hypocreaceae. It used to be known as ''Cephalosporium''.
Description
''Acremonium'' species are usually slow-growing and are initially compact and moist. Their hyphae are fine and hyaline, and pro ...
'', ''
Alternaria
''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...
'', ''
Aspergillus
' () is a genus consisting of several hundred mold species found in various climates worldwide.
''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Miche ...
'', ''
Cladosporium
''Cladosporium'' is a genus of fungi including some of the most common indoor and outdoor molds. Species produce olive-green to brown or black colonies, and have dark-pigmented conidia that are formed in simple or branching chains. Many species ...
'', ''
Phoma
''Phoma'' is a genus of common coelomycetous soil fungi. It contains many plant pathogenic species.
Description
Spores are colorless and unicellular. The pycnidia are black and depressed in the tissues of the host. ''Phoma'' is arbitrarily lim ...
'', ''
Penicillium
''Penicillium'' () is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production.
Some members of the genus produce pe ...
'', ''
Trichoderma
''Trichoderma'' is a genus of fungi in the family Hypocreaceae that is present in all soils, where they are the most prevalent culturable fungi. Many species in this genus can be characterized as opportunistic avirulent plant symbionts. This ref ...
chytrid
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrid ...
, a primitive fungus that infects
green algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...
in estuaries. It obtains nutrients from the host alga and produces swimming
zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves.
Diversity Flagella types
Zoospores may possess one or mo ...
s that must survive in open water, a low nutrient environment, until a new host is encountered. Another fungus, '' Ascochyta salicorniae'', found growing on
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
is being investigated for its action against
malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...
American lobster
The American lobster (''Homarus americanus'') is a species of lobster found on the Atlantic Ocean, Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, norther ...
''(Homarus americanus)'', like many other marine
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
s, incubates its eggs beneath its tail segments. Here they are exposed to water-borne micro-organisms including fungi during their long period of development. The lobster has a
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
relationship with a
gram-negative bacterium
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...
that has anti-fungal properties. This bacterium grows over the eggs and protects them from infection by the pathogenic fungus-like
oomycete
Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the resul ...
tyrosol
Tyrosol is an organic compound with the formula . Classified as a phenylethanoid, i.e. a derivative of phenethyl alcohol, It is found in a variety of natural sources. The compound is colorless solid. The principal source in the human diet is ol ...
, a 4-hydroxyphenethyl alcohol, an
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
substance also produced by some terrestrial fungi. Similarly, a
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...
found in estuaries, '' Palaemon macrodactylis'', has a symbiotic bacterium that produces 2,3-indolenedione, a substance that is also toxic to the oomycete ''Lagenidium callinectes''.
Vertebrates
Whale
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...
s,
porpoise
Porpoises are a group of fully aquatic marine mammals, all of which are classified under the family Phocoenidae, parvorder Odontoceti (toothed whales). Although similar in appearance to dolphins, they are more closely related to narwhals an ...
s and
dolphin
A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...
s are susceptible to fungal diseases but these have been little researched in the field. Mortalities from fungal disease have been reported in captive killer whales; it is thought that stress due to captive conditions may have been predisposing. Transmission among animals in the open sea may naturally limit the spread of fungal diseases. Infectious fungi known from killer whales include ''
Aspergillus fumigatus
''Aspergillus fumigatus'' is a species of fungus in the genus ''Aspergillus'', and is one of the most common ''Aspergillus'' species to cause disease in individuals with an immunodeficiency.
''Aspergillus fumigatus'', a saprotroph widespread in ...
'', ''
Candida albicans
''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is us ...
'' and ''
Saksenaea vasiformis
''Saksenaea vasiformis'' is an infectious fungus associated with cutaneous or subcutaneous lesions following trauma. It causes opportunistic infections as the entry of the fungus is through open spaces of cutaneous barrier ranging in severity fr ...
''. Fungal infections in other
cetacea
Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...
ns include ''
Coccidioides immitis
''Coccidioides immitis'' is a pathogenic fungus that resides in the soil in certain parts of the southwestern United States, northern Mexico, and a few other areas in the Western Hemisphere.
Epidemiology
''C. immitis'', along with its relati ...
'', ''
Cryptococcus neoformans
''Cryptococcus neoformans'' is an encapsulated yeast belonging to the class Tremellomycetes and an obligate aerobe that can live in both plants and animals. Its teleomorph is a filamentous fungus, formerly referred to ''Filobasidiella neoformans' ...
Rhizopus
''Rhizopus'' is a genus of common saprophytic fungi on plants and specialized parasites on animals. They are found in a wide variety of organic substances, including "mature fruits and vegetables", jellies, syrups, leather, bread, peanuts, and t ...
'' sp., ''
Aspergillus flavus
''Aspergillus flavus'' is a saprotrophic and pathogenic fungus with a cosmopolitan distribution. It is best known for its colonization of cereal grains, legumes, and tree nuts. Postharvest rot typically develops during harvest, storage, and/or t ...
'', ''
Blastomyces dermatitidis
''Blastomyces dermatitidis'' is a dimorphic fungus that causes blastomycosis, an invasive and often serious fungal infection found occasionally in humans and other animals. It lives in soil and wet, decaying wood, often in an area close to a wate ...
Histoplasma capsulatum
''Histoplasma capsulatum'' is a species of dimorphic fungus. Its sexual form is called ''Ajellomyces capsulatus''. It can cause pulmonary and disseminated histoplasmosis.
''H. capsulatum'' is "distributed worldwide, except in Antarctica, but m ...
'', ''
Mucor
''Mucor'' is a microbial genus of approximately 40 species of molds in the family Mucoraceae. Species are commonly found in soil, digestive systems, plant surfaces, some cheeses like Tomme de Savoie, rotten vegetable matter and iron oxide resid ...
'' sp., ''
Sporothrix schenckii
''Sporothrix schenckii'', a fungus that can be found worldwide in the environment, is named for medical student Benjamin Schenck, who in 1896 was the first to isolate it from a human specimen. The species is present in soil as well as in and on l ...
'' and ''
Trichophyton
''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized ...
'' sp.
Salmonid
Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...
s farmed in cages in marine environments may be affected by a number of different fungal infections. ''
Exophiala salmonis
''Exophiala'' is a genus of anamorphic fungi in the family Herpotrichiellaceae. The widespread genus contains 28 species. The genus was formally described by J. W. Carmichael in 1966.
''Exophiala'' has been implicated in causing 'saxophone lung ...
'' causes an infection in which growth of hyphae in the kidneys causes swelling of the abdomen. A cellular response by the fish aims to isolate the fungus by walling it off. Fish are also susceptible to fungus-like
oomycetes
Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result ...
including '' Branchiomyces'' which affects the gills of various fishes, and ''
Saprolegnia
''Saprolegnia'' is a genus of water moulds often called cotton moulds because of the characteristic white or grey fibrous patches they form. Current taxonomy puts ''Saprolegnia'' as a genus of the heterokonts in the order Saprolegniales.
Habits
...
'' which attacks damaged tissue.
Marine sediment
Ascomycota, Basidiomycota, and Chytridiomycota have been observed in
marine sediment
Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles have their origins in soil and rocks and have been transported from the land to the sea, mainly ...
s ranging in depth from 0 to 1740 meters beneath the ocean floor. One study analyzed subsurface samples of marine sediment between these depths and isolated all observable fungi. Isolates showed that most subsurface fungal diversity was found between depths of 0 to 25 meters below the sea floor with ''
Fusarium oxysporum
''Fusarium oxysporum'' (Schlecht as emended by Snyder and Hansen), an ascomycete fungus, comprises all the species, varieties and forms recognized by Wollenweber and Reinking within an infrageneric grouping called section Elegans. It is part of ...
'' and ''Rhodotorula mucilaginosa'' being the most prominent. Overall, the ascomycota are the dominant subsurface phylum. Almost all fungal species recovered have also been observed in terrestrial sediments with spore-sourcing indicating terrestrial origin.
Contrary to previous beliefs, deep subsurface marine fungi actively grow and germinate, with some studies showing increased growth rates under high hydrostatic pressures. Though the methods by which marine fungi are able to survive the extreme conditions of the seafloor and below is largely unknown, ''
Saccharomyces cerevisiae
''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been o ...
'' shines some light onto adaptations that make it possible. This fungus strengthens its outer membrane in order to endure higher hydrostatic pressures.
Several sediment-dwelling marine fungi are involved in biogeochemical processes. ''Fusarium oxysporum'' and ''
Fusarium solani
''Fusarium solani'' is a species complex of at least 26 closely related filamentous fungi in the division Ascomycota, family Nectriaceae. It is the anamorph of ''Nectria haematococca''. It is a common soil fungus and colonist of plant materials ...
'' are denitrifiers both in marine and terrestrial environments. Some are co-denitrifying, fixing nitrogen into nitrous oxide and dinitrogen. Still others process organic matter including carbohydrate, proteins, and lipids. Ocean crust fungi, like those found around hydrothermal vents, decompose organic matter, and play various roles in manganese and arsenic cycling.
Sediment-bound marine fungi played a major role in breaking down oil spilled from the Deepwater Horizons disaster in 2010. ''Aspergillus,'' ''Penicillium'', and ''Fusarium'' species, among others, can degrade high-molecular-weight hydrocarbons as well as assist hydrocarbon-degrading bacteria.
Arctic marine fungi
Marine fungi have been observed as far north as the Arctic Ocean. Chytridiomycota, the dominant parasitic fungal organism in Arctic waters, take advantage of phytoplankton blooms in brine channels caused by warming temperatures and increased light penetration through the ice. These fungi parasitize diatoms, thereby controlling algal blooms and recycling carbon back into the microbial food web. Arctic blooms also provide conducive environments for other parasitic fungi. Light levels and seasonal factors, such as temperature and salinity, also control chytrid activity independently of phytoplankton populations. During periods of low temperatures and phytoplankton levels, ''
Aureobasidium
''Aureobasidium'' is a genus of fungi belonging to the family Dothioraceae.
The genus was first described by Pierre Viala and Gaston Boyer in 1891.
Species
The genus contains 26 species:
*'' Aureobasidium aleuritis''
*'' Aureobasidium apocry ...
'' and ''
Cladosporium
''Cladosporium'' is a genus of fungi including some of the most common indoor and outdoor molds. Species produce olive-green to brown or black colonies, and have dark-pigmented conidia that are formed in simple or branching chains. Many species ...
'' populations overtake those of chytrids within the brine channels.
Food webs and the mycoloop
Human uses
Biomass processors
Medical
Marine fungi produce antiviral and antibacterial compounds as metabolites with upwards of 1,000 having realized and potential uses as anticancer, anti-diabetic, and anti-inflammatory drugs.
The antiviral properties of marine fungi were realized in 1988 after their compounds were used to successfully treat the H1N1 flu virus. In addition to H1N1, antiviral compounds isolated from marine fungi have been shown to have virucidal effects on
HIV
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
,
herpes simplex
Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected.
Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold ...
1 and 2,
Porcine Reproductive and Respiratory Syndrome Virus
''Betaarterivirus suid 1'', formerly ''Porcine reproductive and respiratory syndrome virus'' (PRRSV), is a virus that causes a disease of pigs, called porcine reproductive and respiratory syndrome (PRRS), also known as blue-ear pig disease (in C ...
, and
Respiratory Syncytial Virus
Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. ...
. Most of these antiviral metabolites were isolated from species of ''
Aspergillus
' () is a genus consisting of several hundred mold species found in various climates worldwide.
''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Miche ...
'', ''
Penicillium
''Penicillium'' () is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production.
Some members of the genus produce pe ...
'', ''
Cladosporium
''Cladosporium'' is a genus of fungi including some of the most common indoor and outdoor molds. Species produce olive-green to brown or black colonies, and have dark-pigmented conidia that are formed in simple or branching chains. Many species ...
'', ''
Stachybotrys
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
'', and ''Neosartorya''. These metabolites inhibit the virus’s ability to replicate, thereby slowing infections.
Mangrove-associated fungi have prominent antibacterial effects on several common pathogenic human bacteria including, ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...
'' and ''
Pseudomonas aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aerugi ...
''. High competition between organisms within mangrove niches lead to increases in antibacterial substances produced by these fungi as defensive agents. ''Penicillium'' and ''Aspergillus'' species are the largest producers of antibacterial compounds among the marine fungi.
Various deep-sea marine fungi species have recently been shown to produce anti-cancer metabolites. One study uncovered 199 novel cytotoxic compounds with anticancer potential. In addition to cytotoxic metabolites, these compounds have structures capable of disrupting cancer-activated
telomerase
Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat sequence to the 3' end of telomeres. A telomere is a region of repetitive sequences at each end of the chromosomes of most euka ...
s via DNA binding. Others inhibit the
topoisomerase
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues i ...
enzyme from continuing to aid in the repair and replication of cancer cells.
See also
* ''
Aspergillus sydowii
''Aspergillus sydowii'' is a pathogenic fungus that causes several diseases in humans. It has been implicated in the death of sea fan corals (''Gorgonia'' spp.) in the Caribbean Sea.
Taxonomy
The species was first described in 1913 as ''Sterigm ...
Psathyrella aquatica
''Psathyrella aquatica'' is a species of fungus from Oregon, first described in the journal ''Mycologia'' in 2010. It represents the first ever report of a gilled basidiomycete fruiting underwater.
Discovery
It was found by Southern Oregon Un ...