Snails Sneak across a Leptothrix discophora Film
December 11, 2014
I’m back in the archives again, still in 2002. I took this photo October 12. The drought made the year 2002 especially good for sighting Leptothrix discophora films. I think that’s because the iron, which the L. discophora breathes, was concentrated in the remaining river water. You can’t see the snails here—and I’ve never seen one alive in the Vermilion River—because they are nocturnal. It’s their tracks you see sneaking across the film at the top of this photograph. The bright yellow substance under the iridescent film is schwertmannite, a substance composed of iron, oxygen, hydrogen, and sulfur. Biologists suppose that it is produced by an unknown bacterium.
Romancing Reality 