Fungal fight club

Battles between mushrooms don’t make a sound, but they’re violent. “Good fighters can kill the less-good ones and take over their territories,” says mycologist Lynne Boddy of Cardiff University in Wales. “There are battles royal going on all the time.”

Combat between fungal individuals is a bit like war between heaps of spaghetti. The main bodies of fungi are networks of long, thin strands called hyphae that insinuate themselves into anything they can eat: tree trunks, plant roots, dung and so on. Defending a food source or wresting a few more millimeters of turf away from a rival can prolong life. So fungi don’t let a lack of teeth, claws or eyes diminish their ferocity. Boddy studies toadstool-forming basidiomycetes, a group rife with combatants that poison opponents or release enzymes that dissolve their flesh.

“I’m a great fight-goer,” Boddy says. Hundreds of times, she estimates, she has brought fungi in from the wild, set up matches in lab dishes or wood blocks and documented duels lasting weeks. She watches for the hairlike strands to exude chemical droplets, sometimes blood-red. Then she tests the air above the drops for toxic gases wafting toward the enemy. “It’s like gas warfare in the trenches,” she says.

Fungi struggling for territory remind Boddy of a sports league. She has found that bear’s head tooth fungus (Hericium coralloides), which bursts out of tree trunks in delicate, white cascades, usually whips an artist’s conk fungus. But the bear’s head in turn succumbs to a species called hairy parchment. A death match found that the strands of the ferocious sulfur tuft mushroom (inset, upper right) got whomped by Phanerochaete velutina.

Some fungi excel at both offense and defense, others at just one or the other. A few, poor things, are skilled at neither. But as in sports rankings, “sometimes there can be a giant killer from low down,” she says, and a weak competitor beats a favorite.

And as in sports, heat or soggy conditions brings out the greatness in some competitors but dooms others. Boddy’s sports analogy has its limits, though. Climate change can affect who wins fights, she and her colleagues reported this year in Fungal Ecology, but the outcomes depend on more than weather. Shifts in league rank also depend on the extent of nibbling by small woodland arthropods.

FUNGI FIGHT  A tough match between the strands of two ferocious fighters: a sulfur tuft mushroom (top right) and Phanerochaete velutina (bottom left).

Courtesy of L. Boddy