The family Chaetocladiaceae was first proposed by Brefeld (1881; as Chaetocladieen), but Fischer (1892) was the first to provide the correct Latin suffix. The family initially was reserved for only the unispored genus of Mucorales known at that time, Chaetocladium. The family later was recognized by several students of the order (Schröter, 1893; Lendner, 1908; Fitzpatrick, 1930). Later, other unispored taxa, Choanephora and Cunninghamella, were transferred to the Chatocladiaceae (Lender, 1908). Subsequently, Choanephora and Cunninghamella were placed in families of their own, and Chaetocladium was transferred to Thamnidiaceae (Hesseltine, 1955; Zycha et al., 1969; Hesseltine and Ellis, 1973; Benny and Benjamin, 1975, 1976; Benjamin, 1979). Mil’ko and coworkers (Pidoplichko and Mil’ko, 1971; Mil’ko, 1974) included Chaetocladium and other unrelated genera of Mucorales having unispored sporangiola in their very heterogenous concept of Cunninghamellaceae. Mil’ko and Beljakova (1967) transferred Thamnocephalis to Chaetocladium, a classification followed by Pidoplichko and Mil’ko (1971) and Mil’ko (1974). Thamnocephalis is treated as a member of the Sigmoideomycetaceae (Zoopagales) here.

Chaetocladium and Dichotomocladium (Benny and Benjamin, 1975, 1976) were included in the Chaetocladiaceae (Benny and Benjamin, 1993) because of similarities in their anamorphs. All of the taxa placed in the family at that time produced a pedicellate, columellate, unispored sporangiolum with a readily separable, persistent wall, and spinose branches.

A data set consisting of six taxa from the Mortierellales and 75 spp. containing at least one species all of the genera in culture of the Mucorales (tef-1a, 18S rDNA, 28S rDNA, morphology) of O’Donnell et al. (2001) showed that the Chaetocladium clade had 56% bootstrap support (BP). Voigt and Olsson (2008) analyzed a data set (act, tef-1a, 18S rRNA, 28S rRNA) containing selected species of 50 genera of the Mucorales by neighbor-joining (100% BP) and strict consensus (97% BP) that yielded much better support for the Chaetocladiaceae

Dichotomocladium is not included in the Chaetocladiaceae because its affinities have been demonstrated to be with the Absidia blakesleeana—A. corymbifera clade (now the Lichtheimia clade, Lichthemiaceae; Hoffmann et al. 2009) by O’Donnell et al (2001) or the Syncephalastrum or Lichtheimia clades by Voigt and Olsson (2008).

Chaetocladium is the only genus in the Chaetocladiaceae. Chaetocladiaceae is treated as a synonym of the Mucoraceae by Cannon and Kirk (2007) and Kirk et al. (2008). Chaetocladium can be found in nature as a facultative, gall-forming parasite of other members of the Mucorales (Hoffmann and Voigt, 2009). Species of Chaetocladium have been isolated from dung and soil (Benny and Benjamin, 1976; Richardson, 2005). Chaetocladium does not appear to be of any economic value.

Chaetocladiaceae Fischer, 1892 [in Rabenhorst’s Kyptogamen-Flora von Deutschland, Oesterreich und der Schweiz. Zweite Aufl. I(IV). Phycomycetes, p. 177] (Benny, 1973-monograph of Thamnidiaceae with keys and descriptions; Benny and Benjamin, 1975, 1976).

Sporophores erect or ascending, branched, arising directly from the substrate mycelium, galls, or stolons; may produce chlamydospores. Fertile hyphae branched, terminating in sterile spines. Facultative gall-forming parasites of other Mucorales. Sporangiola unispored, columellate, pedicellate; wall persistent and separable from the sporangiospore, covered with spines composed of sporangiolar wall material; borne on fertile vesicles arising from one of the branches of the main sporophore. Zygospores with a rough or wavy zygosporangial wall; suspensors opposed, distinctly unequal to more or less equal, nonappendaged. Psychrophilic or mesophilic. A facultative, gall-forming parasite of other Mucorales in nature.

Type and only genus: Chaetocladium Fresenius.

Synopsis of Genera

CHAETOCLADIUM Fresenius, 1863 (Beitr. Mykol., p. 97); 2 spp. (Benny and Benjamin, 1976 -ILLUS. and KEY TO SPP.; O’Donnell, 1979-illus.; Hoffmann and Voigt, 2009-illus. and phylogeny).

Genera Not Accepted Here but Included in Chaetocladiaceae by Some Authors

[Choanephora—see Choanephoraceae (Mucorales)]

[Cunninghamella—see Cunninghamellaceae (Mucorales)]

[Dichotomocladium—see Synopsis of Genera of Unknown Affinity (Mucorales)].


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Cannon, P.F., and P.M. Kirk. 2007. Fungal families of the world. CAB International. Wallingford, United Kingdom. 456 p.

Fischer, A. 1892. Phycomycetes In: L. Rabenhorst. Kryptogamen-Flora von Deutschland, Oesterreich und der Schweiz. Zweite Auflage. Band I, Abth. IV. Eduard Kummer, Leipzig, Germany. 505 p.

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Hoffmann, K. and K. Voigt. 2009. Absidia parricida plays a dominant role in biotrophic fusion parasitism among mucoralean fungi (Zygomycetes): Lentamyces, a new genus for A. parricida and A. zychae. Plant Biology 10: 537-554.

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Voigt, K., and I. Olsson. 2008. Molecular phylogenetic and scanning electron microscopical analysis places the Choanephoraceae and the Gilbertellaceae in a monophyletic group within the Mucorales (Zygomycetes, Fungi). Acta Biologica Hungarica 59: 365-383.

Zycha, H., R. Siepmann, and G. Linnemann. 1969. Mucorales eine Beschreibung aller Gattungen und Arten dieser Pilzgruppe. Lehre, J. Cramer. 355 p.

Updated Jun 01, 2010