The Mucorales is the largest and best studied order of

zygomycete Zygomycota, or zygote fungi, is a former phylum, division or phylum of the kingdom Fungi. The members are now part of two Phylum, phyla: the Mucoromycota and Zoopagomycotina, Zoopagomycota. Approximately 1060 species are known. They are mostly t ...

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 ...

. Members of this order are sometimes called pin molds. The term mucormycosis is now preferred for infections caused by molds belonging to the order Mucorales.

Systematics

The order includes: 11

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

, 56

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

, and approximately 300

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 ...

. Mucoralean classification has traditionally been based on morphological, developmental, and ecological characteristics. Recently,

molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

data has revealed, that some aspects of traditional classification are quite artificial. For example, the

Mucoraceae The Mucoraceae are a family of fungi of the order Mucorales, characterized by having the thallus not segmented or ramified. Pathogenic genera include '' Absidia'', '' Apophysomyces'', ''Mucor'', ''Rhizomucor'', and '' Rhizopus''. According to a ...

is believed to be

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

, as are the

Thamnidiaceae The Mucoraceae are a family of fungi of the order Mucorales, characterized by having the thallus not segmented or ramified. Pathogenic genera include ''Absidia'', ''Apophysomyces'', ''Mucor'', ''Rhizomucor'', and ''Rhizopus''. According to a 2008 ...

, Chaetocladiaceae and Radiomycetaceae. Some of the genera, (including ''

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 ...

'', ''

Absidia ''Absidia'' is a genus of zygote fungi in the family Cunninghamellaceae. ''Absidia'' species are ubiquitous in most environments where they are often associated with warm decaying plant matter, such as compost heaps. Some species in the genus ...

'' and ''

Backusella ''Backusella'' is the sole genus of zygote fungi in the family Backusellaceae, which is classified in the order Mucorales. Members of this genus have been often isolated from plant litter, from locations around the world. Taxonomy C. W. Hessel ...

'') appear to be polyphyletic. Today, the traditional system is still largely in use, as further studies are needed to reconcile morphological and molecular concepts of families and genera.

Families

The order consists of the following families: * ''

Backusellaceae ''Backusella'' is the sole genus of zygote fungi in the family Backusellaceae, which is classified in the order Mucorales. Members of this genus have been often isolated from plant litter, from locations around the world. Taxonomy C. W. Hessel ...

'' * '' Choanephoraceae'' * ''

Cunninghamellaceae The ''Cunninghamellaceae'' are a family of fungi in the order Mucorales. Taxonomy At one time, this family contained four genera.Hesseltine C. W. & J. J. Ellis. 1973. Mucorales. ''in'': The Fungi: An Advanced Treatise. Volume 5B. A Taxonomic Rev ...

'' * ''

'' * '' Mycotyphaceae'' * '' Phycomycetaceae'' * ''

Pilobolaceae The ''Pilobolaceae'' are a family of fungi in the Mucorales order. Generally, species in this family have a widespread distribution, although there are some that are restricted to tropical and subtropical regions. This family includes two genera: ...

'' * '' Radiomycetaceae'' * ''

Saksenaeaceae The Saksenaeaceae are a family of fungi in the order Mucorales. It was circumscribed in 1974 by J.J. Ellis and Clifford Hesseltine. Description This family is characterized by having sporangia that are lageniform and columellate. Zygospore A zyg ...

'' * '' Syncephalastraceae'' * '' Umbelopsidaceae''

Description

Mucoralean fungi are typically fast-growing, and their wide

hypha 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 ...

e (''long, filamentous structures'') lack

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

( multi-perforate septa are present only in

sporangiophore {{Short pages monitor