Figs 1-2) Loosely coiled, regularly septate aerial sporophores of C. spiralis. Fig 3) Asexual reproduction is via the production of unispored sporangia that are borne on special lateral branches called sporocladia. Fig 4) Mature striate sporangia. Images by Kerry O'Donnell.

Coemansia spiralis Eidam (RSA 1278 = CBS 304.76 = IMI 140078), which is classified within Phylum Zoopagomycota, Order Kickxellales (Spatafora et al. 2016), was originally isolated from dung collected in Baja California, Mexico by R.K. Benjamin in 1963.  This saprophyte grows and sporulates on a number of common agar media where it produces loosely coiled, regularly septate aerial sporophores (Figs. 1-2).  Molecular phylogenetic data indicate that a species that produces tightly coiled sporophores, Spirodactylon aureum, is nested within Coemansia (O’Donnell et al. 1998).   Asexual reproduction is via the production of unispored sporangia that are borne on special lateral branches called sporocladia (Fig. 3).  When the striate sporangia reach maturity (Fig. 4), they are released into a droplet, which might facilitate dispersal by water.  In species of Coemansia known to possess a sexual cycle, it involves the production of smooth-walled zygospores, following fusion of undifferentiated hyphae.  A recent multilocus molecular phylogenetic analysis resolved the Kickxellales as sister to an enigmatic trichomycete-like fungus, Orphella dalhousiensis (Tretter et al. 2014).  The latter species is an endosymbiont of stonefly nymphs from streams in Nova Scotia, Canada.  The whole-genome sequence of C. spiralis was generated as part of the 1000 Fungal Genome Project (http://1000.fungalgenomes.org/home/), which is focused on advancing our understanding of evolution of the early diverging fungi.

References:

O’Donnell K, Cigelnik E, Benny GL. 1998. Phylogenetic relationships among the Harpellales and Kickxellales. Mycologia 90:624─639.

Spatafora JW, Chang Y, Benny GL, Lazarus K, Smith ME, Berbee ML, Bonito G, Corradi N, Grigoriev I, Gryganskyi A, James TY, O’Donnell K, Roberson RW, Taylor TN, Uehling J, Vilgalys R, White MM, Stajich JE. 2016. A phylum-level phylogenetic classification of zygomycete fungi based on genome-scale data. Mycologia 108:1028─1046.

Tretter ED, Johnson EM, Benny GL, Lichtwardt RW, Wang Y, Kandel P, Novak SJ, Smith JF, White MM. 2014. An eight-gene molecular phylogeny of the Kickxellomycotina, including the first phylogenetic placement of Asellariales. Mycologia 106:912─935.