array9

Nail fungus spores are eaten by exmoor ponies and then poo'd out where the fruiting bodies appear, and subsequently shoot out their own spores.

 I dont know the mechanisms but it seems likely that the ponies stomach stimulates the spores to develop into their myceliae, which then develop fruiting bodies, that fire out their spores.  This maybe just digesting the outer covering of the spore, for just the right amount of time. Different species or varieties of grazers may get the timing wrong.  Or even getting the mycelia starting to develop inside the stomach.

But does one spore produce one fruiting body on one pony poo?

The mycelia could develop and divide while in the ponies stomach, and therefore have several segments in several poo's.  And similarly once in a poo, a single mycelia could also divide there. Or could one contected mycelium have more than one fruiting body?

The best strategy is not obvious.  You obviously would like one spore to be capable of quickly multiplying to many spores.  So maybe there is splitting so the one spore infects multiple poo's with multiple seperate treads of  mycelia, each producing a sack of spores.  Indeed one would like some mycelia to have a long life in the gut, producing an endless stream of infected turds.

The mycelia could also split in the turd itself.

I feel my observations support the view that no splitting occurs inside the pony, and any splitting occurs outside.  An individual turd often has more than one fruiting body, but mostly one poo only has one turd with fruiting bodies.  This rather implies post defication splitting.

The top open layers of the fungi often merge to form a big surface area, and that might imply very closely related origins,  but i am out of my depth here.

Martin