Drhoz! (drhoz) wrote in wtf_nature,

Assorted Parasitic Fungi

This is going to be a brief overview - I could happily waffle on about parasitic fungi, for weeks, but I suspect you'll prefer a relatively brief entry suitably tagged, as opposed to 50-odd entries clogging up your friends-list.

A very few interesting things about parasitic fungi, off the top of my head. Not that the fungi in question are off the top of my head, altho Dandruff, Cradle Cap, tinea, and ringworm are all fungal parasites of humans.

As are thrush, various forms of miner's lung disease, and strangest of all, the fungus Schizophyllum commune. Usually, Schizophyllum is perfectly content to eat dead wood and nothing else. But sometimes it decides that the inside of your head makes a suitable substitute. (Perhaps that's where the phrase "Thick as two short planks" comes from?) If you're REALLY unlucky it'll decide to grow into actual mushrooms whilst it's there. It's probably have sex in there too. A lot of sex. It has 28,000 distinct genders.

Aspergilliosis is another lung parasite - a bird can have it for years, then die overnight if stressed, as many a zoo has discovered upon arrival of a new and expensive exhibit.

Chytrid fungi, previously known only from invertebrates, are now known to be exterminating frog populations worldwide, including, tragically, both species of Australia's very own Gastric-brooding Frog. The saddest thing is it may well have been some innocent herpetologist that unwittingly spread the fungus in the first place.

Cordyceps fungus I know have shown up here before - also known as 'vegetable caterpillars', unfortunate caterpillars, spiders, ants etc that have accidentally eaten a spore. The fungus then consumes the entire animal from inside out then bursts out thru the head. An episode of the X-files had something similar bursting from the victim's throat. A Himalayan species is being massively over-collected because the Chinese claim it's great for Olympic athletes.

I even use parasitic fungi in my work - indirectly, I admit. One of the chemicals I can use is not a repellent. A termite that picks up a sub-lethal dose of it gets clumsy, twitchy as a speed freak, and forgets to groom itself. This, for a termite, is bad news, because they live in soil and nests with 97% humidity and they promptly come down with a bad case of of fungus. All the time they're spreading the poison, as well. The result is a slow death by fungal plague for the entire colony.

Then there's the plant pathogens - the rusts, the smuts, the fungal galls and cankers. Some of them, such as Cedar-Apple Rust, cycle between different hosts.

The picture above is of that rust, Gymnosporangium juniperi-virginianae, growing on a cedar. Why is it not growing on an apple, I hear you ask? Because, like so many of the animal parasites I've be discussing later, this fungus alternates between hosts. In one part of its life-cycle, it is a fairly standard rust fungus of apples. ( A related species infects quinces and other rosaceous plants)

Then next year it infects a conifer - junipers or red cedars usually. It promotes the growth of a brown, woody, tough gall, resembling a juniper pine-cone.

And the next time it rains, the gall suddenly unfolds into this vividly coloured, jelly-like and, apparently, edible thelial horns. Pretty isn't it?

And here, one of the most interesting fungal pathogens I know - Puccinia monoica

title or description

Puccinias are rust fungi unusual in the lengths they go to to spread from plant to plant - they actually ATTRACT an insect to do it for them, rather then relying on the wind or chance wanderings.

P. monoica infects Rocky Mountain wild mustard, whereupon it promptly destroys the mustards reproduction ability, and deforms the remaining stalks and leaves into a bright yellow 'flower'. It even has 'nectaries' - glands designed to attract and reward any insect that thinks it's a real flower. And they even have the same ultraviolet stripes used by other flowers to steer bees to the pollen! or in this case, the spores.

The picture above (and the link) has more info. The pic itself shows a single plant - the bit on the left is uninfected and has the normal tall purple flower stalk of a wild mustard - the yellow daisy-looking thing in the fungal fake.

A few other links to more rust fungi that mutate the plant host into a flower-like structure

Ergot, a parasite of grain, has been one suggested cause for the sorry business at Salem, Mass., because of its very potent hallucinogenic properties (the other suggestion is that they were all massive jerks). Another fungus caused the Irish Potato famine. And Gibberella, that causes 'foolish seedling' disease in rice, was the first known source of the very important PLANT hormones, the gibberellins. The fungus simply produces so much more that the host grow up so tall and spindly that it falls over where the fungus can rot and eat it.

Two other cultural refs - the Romans had the god Robigus, personification of rust fungus. And Judge Dredd featured a parasitic fungus in the episode Fungus, that amongst other victims consumed the former mayor of the city. It was named in his honour, and his last words as the fungi were erupting from his skin were "Please don't eat me"
Tags: aspergilliosis, canker, chytrid, cordyceps, disease, ergot, fungi, fungus, gastric-brooding frog, gymnosporangium juniperi-virginianae, mushroom, parasite, potato blight, puccinia monoica, ringworm, schizophyllum commune, sex, termites, thrush, tinea
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