Blastocladiomycota is one of the currently recognized phyla within the kingdom Fungi.Hibbett DS et al. 2007. A higher-level phylogenetic classification of the fungi. Mycological Research 111:509–47. Blastocladiomycota was originally the order Blastocladiales within the phylum

Chytridiomycota 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. Chytri ...

until molecular and zoospore ultrastructural

characters Character or Characters may refer to: Arts, entertainment, and media Literature * ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk * ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to The ...

were used to demonstrate it was not monophyletic with Chytridiomycota. The order was first erected by Petersen for a single genus, ''Blastocladia'', which was originally considered a member of the oomycetes.Sparrow FK. 1960. Aquatic phycomycetes. 2nd ed. Ann Arbor, Michigan: University of Michigan Press. Accordingly, members of Blastocladiomycota are often referred to colloquially as "chytrids." However, some feel "chytrid" should refer only to members of Chytridiomycota.Alexopoulos CJ, Mims CW, Blackwell M. 1996. Introductory Mycology. 4th edition. John Wiley & Sons, Inc. Thus, members of Blastocladiomyota are commonly called "blastoclads" by mycologists. Alternatively, members of Blastocladiomycota, Chytridiomycota, and

Neocallimastigomycota Neocallimastigomycota is a phylum containing anaerobic fungi, which are symbionts found in the digestive tracts of larger herbivores. Anaerobic fungi were originally placed within phylum Chytridiomycota, within Order Neocallimastigales but lat ...

lumped together as the zoosporic true fungi. Blastocladiomycota contains 5 families and approximately 12 genera.Porter TM ‘’etal’’ 2011. Molecular phylogeny of the Blastocladiomycota (Fungi) based on nuclear ribosomal DNA. Fungal Biology 115:381-392. This early diverging branch of kingdom Fungi is the first to exhibit

alternation of generations Alternation of generations (also known as metagenesis or heterogenesis) is the predominant type of life cycle in plants and algae. It consists of a multicellular haploid sexual phase, the gametophyte, which has a single set of chromosomes alte ...

.Kendrick, Bryce. 2000. The Fifth Kingdom. 3rd edition Focus Publishing: Newburyport, MA. As well, two (once) popular model organisms—''

Allomyces macrogynus ''Allomyces macrogynus'' is a species of fungus in the family Blastocladiaceae. It was first described by mycologist Ralph Emerson in 1941 as a variety of '' Allomyces javanicus'', and later given distinct species status in 1954. Its genome ha ...

'' and ''Blastocladiella emersonii''—belong to this phylum.

Morphology

Morphology in Blastocladiomycota varies greatly. For example, members of Coelomycetaceae are simple, unwalled, and plasmodial in nature. Some species in ''Blastocladia'' are monocentric, like the chytrids, while others are polycentric. The most remarkable are those members, such as ''Allomyces'' that demonstrate determinant, differentiated growth.

Reproduction/life cycle

Sexual reproduction

As stated above, some members of Blastocladiomycota exhibit

. Members of this phylum also exhibit a form of sexual reproduction known as anisogamy. Anisogamy is the fusion of two sexual gametes that differ in morphology, usually size. In ''

Allomyces ''Allomyces'' is a genus of fungi in the family Blastocladiaceae. It was circumscribed by British mycologist Edwin John Butler in 1911. Species in the genus have a polycentric thallus and reproduce sexually or asexually by zoospores that have ...

'', the thallus (body) is attached by

rhizoids Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be ...

, and has an erect trunk on which reproductive organs are formed at the end of branches. During the haploid phase, the thallus forms male and female

gametangia A gametangium (plural: gametangia) is an organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. In contrast to gametogenesis in animals, a gametangium is a haploid s ...

that release flagellated gametes. Gametes attract one another using pheromones and eventually fuse to form a Zygote. The germinated zygote produces a diploid thallus with two types of sporangia: thin-walled zoosporangia and thick walled resting spores (or sporangia). The thin walled sporangia release diploid zoospores. The resting spore serves as a means of enduring unfavorable conditions. When conditions are favorable again, meiosis occurs and haploid zoospores are released. These germinate and grow into haploid thalli that will produce “male” and “female” gametangia and gametes.

Asexual reproduction

Similar to

, members of Blastocladiomycota produce asexual zoospores to colonize new substrates. In some species, a curious phenomenon has been observed in the asexual zoospores. From time to time, asexual zoospores will pair up and exchange

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...

but not nuclei.

Ecological roles

Similar to Chytridiomycota, members of Blastocladiomycota are capable of growing on refractory materials, such as pollen, keratin, cellulose, and chitin. The best known species, however, are the parasites. Members of ''Catenaria'' are parasites of

nematodes The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...

, midges, crustaceans, and even another blastoclad, ''Coelomyces''. Members of the genus ''

Physoderma ''Physoderma'' is a genus of chytrid fungi. Described by German botanist Karl Friedrich Wilhelm Wallroth in 1833, the genus contains some species that are parasitic on vascular plants, including '' P. alfalfae'' and '' P. maydis'', ca ...

'' and ''

Urophlyctis ''Physoderma'' is a genus of chytrid fungi. Described by German botanist Karl Friedrich Wilhelm Wallroth in 1833, the genus contains some species that are parasitic on vascular plants, including '' P. alfalfae'' and '' P. maydis'', ca ...

'' are obligate plant parasites. Of economic importance is ''

Physoderma maydis ''Physoderma maydis'' is a species of fungus in the family Physodermataceae. It is a pathogen of the maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian Engli ...

'', a parasite of maize and the causal agent of brown spot disease. Also of importance are the species of ''

'' that parasitize

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as we ...

. However, ecologically, ''

'' are important parasites of many aquatic and marsh

angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

. Also of human interest, for health reasons, are members of ''

Coelomomyces ''Coelomomyces'' is the only genus of fungi in the family Coelomomycetaceae. Species in the genus can be used as agents for the biological control of mosquitoes. Characteristics ''Coelomomyces'' are obligate parasites of mosquitoes and chirono ...

'', an unusual parasite of mosquitoes that requires an alternate crustacean host (the same one parasitized by members of ''Catenaria'') to complete its life cycle. Others that are ecologically interesting include a parasite of water bears and the zooplankter ''

Daphnia ''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembl ...

''.

Taxonomy

Based on the work of Philippe Silar and "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and synonyms from "Part 1- Virae, Prokarya, Protists, Fungi". * Phylum Blastocladiomycota Tehler, 1988 ex James 2006 llomycota Cavalier-Smith 1981; Allomycotina Cavalier-Smith 1998** Class Physodermatomycetes Tedersoo et al. 2018 *** Order Physodermatales Cavalier-Smith 2012 hysodermatineae**** Family

Physodermataceae Physodermatacae is a family of chytrid fungi in the order Physodermatales. Species in the family have a parasitic relationship with the host's physoderma. This family is distinctive in that it contains a thick wall around the sporangia to resist ...

rophlyctidaceae Schroeter 1886***** Genus '' Paraphysoderma'' Boussiba, Zarka & James 2011 ***** Genus ''

'' Wallroth 1833 'Oedomyces''_Saccardo_ex_Trabut_1894.html" ;"title="Oedomyces.html" ;"title="'Oedomyces">'Oedomyces'' Saccardo ex Trabut 1894">Oedomyces.html" ;"title="'Oedomyces">'Oedomyces'' Saccardo ex Trabut 1894***** Genus ''

'' Schröter 1886 ** Class Blastocladiomycetes James 2006 [Allomycetes Cavalier-Smith 1998] *** Order Blastocladiales Petersen 1909 sensu Cavalier-Smith 2012 [Allomycales; Blastocladiineae] **** Genus ''Endoblastidium'' Codreanu 1931 **** Genus ''Polycaryum'' Stempell 1901 **** Genus '' Nematoceromyces'' Doweld 2013 **** Genus ''

Blastocladiella ''Blastocladiella'' is a genus of fungus. Species * '' Blastocladiella anabaenae'' * '' Blastocladiella asperosperma'' * '' Blastocladiella britannica'' * '' Blastocladiella colombiensis'' * '' Blastocladiella cystogena'' * '' Blastocladiella ...

'' Matthews 1937 'Clavochytridium''_Couch_&_Cox_1939;_''Sphaerocladia.html" ;"title="Clavochytridium.html" ;"title="'Clavochytridium">'Clavochytridium'' Couch & Cox 1939; ''Sphaerocladia">Clavochytridium.html" ;"title="'Clavochytridium">'Clavochytridium'' Couch & Cox 1939; ''Sphaerocladia'' Stüben 1939] **** Family Coelomomycetaceae Couch 1962 ***** Genus ''Callimastix'' Weissenberg 1912 ***** Genus ''Coelomycidium'' Debaisieux 1919 ***** Genus ''

'' Keilin 1921 'Zografia''_Bogayavlensky_1922.html" ;"title="Zografia.html" ;"title="' 'Zografia''_Bogayavlensky_1922">Zografia.html"_;"title="'Zografia">'Zografia''_Bogayavlensky_1922****_Family_Sorochytriaceae.html" ;"title="Zografia">'Zografia'' Bogayavlensky 1922">Zografia.html" ;"title="'Zografia">'Zografia'' Bogayavlensky 1922**** Family Sorochytriaceae">Zografia">'Zografia'' Bogayavlensky 1922">Zografia.html" ;"title="'Zografia">'Zografia'' Bogayavlensky 1922**** Family Sorochytriaceae Dewel 1985 ***** Genus ''Sorochytrium'' Dewel 1985 **** Family Catenariaceae Couch 1945 ***** Genus ''Catenaria (fungus), Catenaria'' Sorokin 1889 non Roussel 1806 [''Perirhiza'' Karling 1946] ***** Genus '' Catenophlyctis'' Karling 1965 **** Family Blastocladiaceae Petersen 1909 ***** Genus '' Blastocladiopsis'' Sparrow 1950 ***** Genus '' Microallomyces'' Emerson & Robertson 1974 ***** Genus '' Blastocladia'' Reinsch 1877 ***** Genus ''

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_References

_External_links

*_ {{Taxonbar.html" ;"title="Septocladia">' Septocladia.html"_;"title="'Septocladia">'Septocladia''_Coker_&_Grant_1922

_References

_External_links

*_ {{Taxonbar">from=Q1140791 Blastocladiomycota.html" ;"title="Septocladia'' Coker & Grant 1922">Septocladia.html" ;"title="'Septocladia">'Septocladia'' Coker & Grant 1922

References

External links

* {{Taxonbar">from=Q1140791 Blastocladiomycota"> Aquatic fungi Fungus phyla Fungi by classification