Thursday: 24 August 2006
The first word of the title is: mystery
Everyone got it, but the master naturalist Pablo got it first. I’m guessing them to be deer pellets, but I’ve never seen them other than black and shiny. I would bet that the white coating, as Pablo and FC pointed out as a fungus, is a Zygomycete - the simplest of the terrestrial fungi. We usually see zygomycetes in the form of Rhizopus, bread mold. They’re the first fungi to hit a food source and are the fastest growing. Cup fungi (Ascomycetes) next, and then mushrooms (Basidiomycetes), are respectively slower growing and complete the succession.
Herbivore dung like this can be scooped up and put in a jar, loosely capped. If kept moist (not wet), different sorts of Zygomycetes will appear. Apparently a lot of these dung fungi are highly specialized as to animal species and are already in the dung to start with.
The classic example is Pilobolus. Found in cow dung, this tiny Zygomycete eventually produces photosensitive zygosporangia (tiny spore-filled sacs on a stalk). They bend toward the sun. They’re also fluid filled, and transparent so the sun heats the fluid and the sporangium eventually explodes, popping the spores distances of several feet toward the sun.
This guarantees that the spores will land in the grass, to be eaten by a cow and thereby completing the cycle.
Put a bit of cow dung in that glass jar, and completely cover the jar with aluminum foil to keep the light completely out. Then scratch a tiny hole in the side of the foil so that a pinhole of light is allowed in. After Pilobolus has developed, the spores will be directed to that hole, and will eventually coat it in a small circle of spores. Useless for them of course, but that’s how it works.
Everyone got it, but the master naturalist Pablo got it first. I’m guessing them to be deer pellets, but I’ve never seen them other than black and shiny. I would bet that the white coating, as Pablo and FC pointed out as a fungus, is a Zygomycete - the simplest of the terrestrial fungi. We usually see zygomycetes in the form of Rhizopus, bread mold. They’re the first fungi to hit a food source and are the fastest growing. Cup fungi (Ascomycetes) next, and then mushrooms (Basidiomycetes), are respectively slower growing and complete the succession.
Herbivore dung like this can be scooped up and put in a jar, loosely capped. If kept moist (not wet), different sorts of Zygomycetes will appear. Apparently a lot of these dung fungi are highly specialized as to animal species and are already in the dung to start with.
The classic example is Pilobolus. Found in cow dung, this tiny Zygomycete eventually produces photosensitive zygosporangia (tiny spore-filled sacs on a stalk). They bend toward the sun. They’re also fluid filled, and transparent so the sun heats the fluid and the sporangium eventually explodes, popping the spores distances of several feet toward the sun.
This guarantees that the spores will land in the grass, to be eaten by a cow and thereby completing the cycle.
Put a bit of cow dung in that glass jar, and completely cover the jar with aluminum foil to keep the light completely out. Then scratch a tiny hole in the side of the foil so that a pinhole of light is allowed in. After Pilobolus has developed, the spores will be directed to that hole, and will eventually coat it in a small circle of spores. Useless for them of course, but that’s how it works.
