Sordaria fimicola

Sordaria fimicola is a species of microscopic fungus. It is commonly found in the feces of herbivores. S. fimicola is often used in introductory biology and mycology labs because it is easy to grow on nutrient agar in dish cultures. The most common form of S. fimicola is a dark brown. Certain mutants are grey or tan. A common experiment for an introductory lab class is to cross one of the mutant types with a wild type and observe the ratio of coloring in the offspring. This experiment illustrates the concepts of genetic inheritance in a haploid organism. The eight ascospores are produced inside an ascus. Soradia squashes can give us information about crossing over during meiosis. If no crossing over then there is a 4:4 pattern. 4 black spores, and 4 tan spores all lined up. If crossing over does occur there is a 2:2:2:2 pattern visible, or a 2:4:2 pattern.

Another common lab use is to observe meiosis and mitosis in the fruiting bodies, called perithecia. An interesting feature of S. fimicola is that its fruiting body is phototrophic. Thus, as it grows the stalk will bend toward a light source and when the sac bursts, the spores are shot towards the light.