Pilobolus Life Cycle

Pilobolus Life Cycle image by Photo © George Barron

Pilobolus is a fungi that feeds on the manure of herbivorous animals. Pilobolus is not a parasite that steals nutrients from its host and it does not appear to cause any human, plant or animal diseases. It cannot produce its own food, so it lives on the undigested plants, bacteria, water and minerals ---particularly nitrogen --- in the dung of herbivores.

The Pilobolus life cycle begins when a herbivore defecates. The animal then moves away because animals avoid eating near dung. Pilobolus mycelium, the cobweb-like hyphae through which the fungi eats, grow and feed on the manure.

As the Pilobolus feeds and grows, it develops sporangia, slender stalks topped with small pods that contain the Pilobolus' reproductive spores.

This next step has fascinated scientists since its discovery. The Pilobolus must move because herbivorous animals won't feed near dung piles and Pilobolus needs to be ingested by a herbivore for the essential next phase in its life cycle. So the Pilobolus launches its sporangia into the air, sometimes more than 6 feet. Thus the Pilobolus spreads out over its habitat and significantly increase its chances of being eaten by a cow, deer, horse or other herbivore.

A herbivore feeds on grass containing Pilobolus sporangia. The sporangia passes through the animal's digestive system without harm. The animal defecates the spores.

The Pilobolus mycelium feeds on the dung pile and the cycle of life begins again.

An interesting fact about Pilobolus is that, although it does not cause any diseases, the larva of Dictyocaulus, a roundworm that causes lungworm in herbivorous animals, piggy-backs on the air-borne Pilobolus sporangia to also move away from the exhausted dung pile. This enables Dictyocaulus to also increase its chances of being ingested by a herbivore.

Photo by: Photo © George Barron