Plantwatch: the mushroom that is both delicacy and predator

Oyster mushroom feeds on roundworms using a deadly nerve agent that causes paralysis

A mushroom that eats animals sounds like a horror story. But the oyster mushroom is a full-bloodied carnivore that feeds on roundworms, killing its prey using a nerve gas.

Even though oyster mushrooms are a prized food delicacy, don't be fooled; they kill nematodes, tiny roundworms. The oyster mushroom Pleurotus ostreatus usually grows on dead or dying trees, but the wood has so little protein that the fungus turns to consuming nematodes for nourishment. It uses a lethal array of tiny balls attached to the hypae, the long hair-like filaments of the fungus. When a nematode brushes past a ball it instantly bursts, paralysing and killing the tiny worm in minutes. The fungal filament then penetrates the carcass, dissolving its tissues and sucking out the nutrients.