Mortierella colonies are relatively fast-growing and often spread in overlapping "waves" or lobes. Some have a peculiar odour suggesting garlic. Many species produce a white oily substance in large drops among the aerial hyphae. One group of species, characterized by velvety, odourless colonies, is considered by some mycologists to represent a separate genus Micromucor. The spores (sporangiospores) of Mortierella species are produced inside spherical sporangia at the tips of sporangiophores and are colourless to brownish (sometimes pink in Micromucor). A columella is usually lacking or very poorly developed (compare with Mucor for this feature).
Mortierella species often fail to reproduce under normal laboratory conditions. We have obtained good sporulation by growing the colonies on water agar (agar media containing no nutrients) and incubating at 5-10° C. Growth is slow but sporangia are often abundant. Apparently cold and starvation triggers reproduction.
Some species, such as M. polycephala, produce spherical "chlamydospores". These spores can be large in some species and may be variously roughened. In culture, the chlamydospores may be more conspicuous than the sporangia; in fact sporangia may be absent at first. Similar spores are produced by Histoplasma capsulatum, cause of a serious disease in humans, and by species of Sepedonium
Common in soil and dung. Ref: Gams 1969, 1977; Zycha and Siepmann 1970