For the majority of fungi, the fruiting body produces air dispersed spores that catch upwellings of wind allowing those spores to travel expansive distances. The stinkhorns have evolved a different strategy by producing a sticky, stinky spore filled material called gleba that entice carrion feeding insects to take a nibble, and disperse the spores to other areas of the forest floor. It is pretty standard that the stationary fruiting bodies produce the spores that disperse insane distances. Unsurprisingly, I learned of another group of fungi in which the actual fruiting body is the dispersal agent. The cleistothecial fungi are interesting group of fungi that do just that.
Myxotrichum chartarum is a unique species of fungus. Like I just mentioned, the actual small fruiting body of this species is actually the method of dispersal. By looking closely at its small fruiting bodies, one can see these curved appendages that are seemingly perfect for clinging on to feathers, hair or insects. And when we look the ecology of these organisms, this makes perfect sense.
Many cleistothecial fungi are specialists that decompose keratin; the protein found in hair, nails, horns, and feathers. So, a fruiting body that easily attaches to animals that produce these proteins makes perfect sense. Several other species of cleistothecial fungi are plant parasites, breaking down leaves and stems. The species that are plant parasites don’t have the same morphology as the keratin feeding individuals. The curved appendages that allow the fruiting body to cling to animals doesn’t offer much of a fitness reward for the species that parasitize living plant tissue.
Myxotrichum chartarum. By Jens H Peteren.
The cleistothecial fungus featured today is neither a keratin specialist nor a plant parasite. Myxotrichum chartarum has more of a saprotrophic ecology, specializing in the decomposition of cellulose. In fact, chartarum is the Latin word for paper, since quite often, this species is found breaking down the cellulose rich paper in old books. Although it’s not a keratin specialist, the hook-like appendages aid in its dispersal to suitable habitats. Most likely, its preferred dispersal agent are insects who move along the forest floor in and around cellulose rich woody debris.
Myxotrichum chartarum. R. K. Benjamin 1956.
Fungal spores are most commonly dispersed by wind, while some other fungi entice insects to disperse their spores. Today I learned that the actual fruiting bodies of cleistothecial fungi cling to animals like birds, mammals and insects in hopes of dispersing to a new suitable habitat. Cleistothecial fungi that are keratin specialist happily cling to keratin producing birds and mammals, while cellulose feeding fungi like Myxotrichum chartarum utilize insect dispersers that shuttle these fruiting bodies packed with spores to cellulose rich woody substrates.
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