Fungalpedia – Note 3328, Blastocladiomycota

 

Blastocladiomycota T.Y. James, Mycologia 98(6): 867 (2007) [2006].

Citation when using this data: Wijayawardene NN et al. 2024 – Fungalpedia.

Index Fungorum, Faceoffungi, MycoBank, GenBank.

Classification: Blastocladiomyceta, Fungi.

Thallus monocentric or polycentric, may form hyphae, varies greatly in size and extent or degrees of complexity; zoospore with a single posteriorly directed whiplash-type flagellum possessing a lipid-filled organelle often called a side-body complex (SBC) composed of several lipid droplets, characterized by the presence of distinctive anteriorly located membrane-bounded ribosomal nuclear cap adjacent to the cone-shaped nucleus which abuts the kinetosome, cytoplasmic microtubules extending anteriorly from the proximal (upper) part of the kinetosome (the basal body of the flagellum) to surround the nuclear envelopes, absence of electron opaque plug in the transitional zone at the base of zoospore flagellum. Asexual reproduction through uniflagellated zoospores produced in zoosporangium, sexual reproduction by planogamete (sexual gamete) fusion and life cycle with sporic meiosis displaying alternation of gametophytic and sporophytic generations (James et al. 2006b). 

Life mode and distribution: Saprobic on a wide variety of animal and plant substrates in both aquatic and terrestrial habitats. Some representatives are parasites of algae, fungi, plants and invertebrates of freshwater and soil environments, and occasionally found to be facultatively anaerobic that grow under foul conditions (Sparrow 1960; Karling 1977; James et al. 2006a, b, 2014; Hibbett et al. 2007, Powell 2017). 

Notes: James et al. (2006b) introduced the phylum Blastocladiomycota since it formed a monophyletic clade, distinct from other early divergent lineages in the Kingdom Fungi. Blastocladia Reinsch (Reinsch 1877) the type genus of the phylum Blastocladiomycota was accommodated in its own family, Blastocladiaceae by Petersen (1910). Later, the Order Blastocladiales was introduced by Kanouse (1927). Fitzpatrick (1930) regarded Blastocladiales in the class Phycomycetes (i.e. ‘A class formerly used for Fungi and now treated in Chromista (q.v.) and some fungi (Chytridiomycota and Zygomycota) fide Kirk et al. 2008). However, Alexopoulos (1966) accommodated Blastocladiales in Chytridiomycetes.

Tehler (1988) used the term ‘Blastocladiomycota’, as a division of ‘Subkingdom Eumycota’ but did not provide type details or descriptions thus invalid. Doweld (2001) introduced Blastocladiomycota Doweld 2001 but invalid (Art. 38.1(a) (Shenzhen); ‘Published as ‘nom. nov.’, based on Allomycotina Caval.-Sm., 1998 (David, Constancea 83.16: 5) fide Index Fungorum 2023). Hence, James et al. (2006b) provided proper diagnosis and description of the phylum thus, Blastocladiomycota T.Y. James 2006 [2007] is the correct name. Subsequent studies agreed with the conclusions in James et al. (2006b) and confirmed its phylogenetic placement in the fungal tree (e.g. Hibbett et al. 2007). Porter et al. (2011) showed the family placements of Blastocladiomycota but did not assign/ mention any subphyla or classes but their tree clearly showed the separation of Physodermataceae. Agreeing with Porter et al. (2011), Tedersoo et al. (2018) introduced Subphylum Blastocladiomycotina Tedersoo et al. and the Class Physodermatomycetes Tedersoo et al. Following studies by Wijayawardene et al. (2018b, 2020a) and Voigt et al. (2021) also agreed with the higher-level classification proposed by Tedersoo et al. (2018).

Currently comprises one subphylum (Blastocladiomycotina) and two classes. 

Type genus: Blastocladia Reinsch 1877.

Other accepted species: Species Fungorum – search Blastocladiomycota.

 

References

Alexopoulos CJ, Mims CW, Blackwell M. 1996 – Introductory Mycology, 4th Edition. John Wiley & Sons Inc. New York.

Cavalier-Smith T. 1998 – A revised six-kingdom system of life. Biol Reviews 73:203–266. 

Doweld AB. 2001 – Prosyllabus tracheophytorum. In: Tentamen systematis plantarum vascularium (Tracheophyta). Geos, Moscow.

Fitzpatrick HM. 1930 – The lower fungi Phycomycetes. New York: McGraw-Hill, pp 331.

Hibbett DS, Binder M, Bischoff JF, Blackwell M et al. 2007 – A higher level phylogenetic classification of the fungi. Mycol Res 111(5):509–547.

James TY, Kauff F, Schoch CL, Matheny PB et al. 2006a – Reconstructing the early evolution of Fungi using a six-gene phylogeny. Nature 443:818–822.

James TY, Letcher PM, Longcore JE, Mozley-Standridge SE et al. 2006b – A molecular phylogeny of the flagellated fungi (Chytridiomycota) and description of a new phylum (Blastocladiomycota). Mycologia 98(6):860–871.

James TY, Porter TM, Martin WW. 2014 – Blastocladiomycota. In D. J. McLaughlin & J. W. Spatafora (Eds) The Mycota VII-part A. Springer, New York, pp 177–207.

Kanouse BB. 1927 – A monographic study of special groups of the water molds I. Blastocladiaceae. Am J Bot 14:227–286.

Karling JS. 1977 – Chytridiomycetarum Iconographia. Monticello, New York: Lubrecht Cramer.

Kirk PM, Cannon PF, Minter DW, Stalpers JA et al. 2008 – Ainsworth & Bisby’s dictionary of the fungi, 10th edn. CABI, Wallingford, pp 439.

Petersen HE. 1910 – An account of Danish freshwater Phycomycetes, with biological and systematical remarks. Ann Mycol 8:494–560.

Porter TM, Martin W, James TY, Longcore JE et al. 2011 – Molecular phylogeny of the Blastocladiomycota (Fungi) based on nuclear ribosomal DNA. Fungal Biol 115:381–392.

Powell MJ. 2017 – Blastocladiomycota. In: Archibald, J., Simpson, A., Slamovits, C. (eds) Handbook of the Protists. Springer, Cham.

Reinsch PF. 1877 – Beobachtungen über einige neue Saprolegnieae, über die Parasiten in Desmidienzellen und über die Stachelkugeln in Achlyaschläuchen. Pringsheim’s Jahrbucher fur Wissenschaftliche Botanik 11:283–311.

Sparrow FK. 1960 – Aquatic Phycomycetes. In: Ann Arbor (ed) 2nd ed. University of Michigan Press, Michigan.

Tedersoo L, Sánchez-Ramírez S, Kõljalg U, Bahram M et al. 2018 – High-level classification of the Fungi and a tool for evolutionary ecological analyses. Fungal Divers 90:135–159.

Tehler A. 1988 – A cladistic outline of the Eumycota. Cladistics 4:227–277.

Voigt K, James TY, Kirk PM, de A. Santiago ALCM et al. 2021 – Early-diverging fungal phyla: taxonomy, species concept, ecology, distribution, anthropogenic impact, and novel phylogenetic proposals. Fungal Divers 109:59–98.

Wijayawardene NN, Hyde KD, Al-Ani LKT, Tedersoo L et al. 2020a – Outline of Fungi and fungus-like taxa. Mycosphere 11:1060–1456.

Wijayawardene NN, Pawlowska J, Letcher PM, Kirk PM. 2018b – Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota). Fungal Divers 92:43–129. 

 

Entry by

Nalin N. Wijayawardene, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China, Tropical Microbiology Research Foundation, 96/N/10, Meemanagoda Road, 10230 Pannipitiya, Sri Lanka, Department of Bioprocess Technology, Faculty of Technology, Rajarata University, Sri Lanka

 

Published online 2 October 2026

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