T Minus Ten. Nine. Eight....
Lungworm! And Fungus Cannon!
Dictyocaulus is a genus of nematode worms, parasitic upon large herbivores including cattle, elk, deer, horses, and donkeys. They spend most of their life in the lungs, causing the disease 'Husk'. Their eggs, however, get coughed up and swallowed, and hatch into L1 stage larvae. These do fine in the faeces, and pass through a second and third stage once they get their first taste of the outside world. But they still need to get from the cowpat back into the cow, which presents problems.
Because most animals avoid eating anywhere near their own faeces. Even without lungworm to worry about, there are plenty of other diseases that could make it a case of "Eat Shit And Die" ( eating somebody else's shit presents fewer problems, and indeed plenty of animals will happily get stuck in for the extra nutrients - and koalas wean their babies onto half-digested gumleaves ).
But back to the little L3 lungworms, looking for a way to get from the meadow muffin to some nice tempting grass a good way off. Fortunately, they have a short cut.
Because one of the other temporary gut inhabitants is the fungus Pilobolus. This zygomycete just wants to get from pasture patty to pasture patty, and the best way to do it is via the cow. But then it faces the same problem the worm does - trying to get far enough from the landmine it's in to clean grass somewhere over there. Pilobolus' solution is to bundle its spores into a neat little capsule at the end of a stalk, and fire it off at 180,000g's.
Thankyou </b></a>hayleyscomet for doing the vid, and anjel_kitty for the news, via the mycology group.
The stalks will point directly at the sun, too, the launch bulb doubling as a lens to indicate the best growth direction for the cells below. Even neater, the sporangiums are covered in calcium oxalate crystals on one side, so if they land in a dew drop they flip over and stick down properly.
So, with these spore capsules a mere centimetre overhead, then flying off up to 2 metres (or ricochetting noisily off the lid of the box in the lab ) all the little lungworms have to do is climb the launch tower and get on board. No doubt they have The Right Stuff, because lungworm remains a serious disease of many large domestic herbivores.