This is no ordinary dust, though. It came from our birdbath that had been dry since last fall. I scraped off some of the crust of cyanobacteria (algae) from the bottom and placed the pieces in a small petri dish.
Then I added a little bit of water* to the dish and set it aside. An hour later, life had returned to it in the form of bdelloid rotifers. During the winter I had the birdbath turned upside down to prevent ice forming in it. Dry rotifers obviously survived in the crust. They didn’t mind the freezing temperatures either.
Bdelloids share their ability to remain alive in a desiccated state with an odd assortment of other animals, including certain nematodes and tardigrades, some insect larvae and the brine shrimp Artemia. Desiccation survival (anhydrobiosis) probably evolved independently multiple times, because different protective mechanisms appear to be in operation in different animal groups. For example, nematodes, tardigrades and Artemia accumulate a disaccharide called trehalose prior to drying, whereas bdelloids don't (Lapinski & Tunnacliffe, 2003; Hengherr et al., 2008).
Previous posts about bdelloids: here, here and here.
*Tap water that had been filtered thru charcoal and heated to near boiling (to make coffee) and then cooled.
Steffen Hengherr, Arnd G. Heyer, Heinz-R. Köhler, Ralph O. Schill. 2008. Trehalose and anhydrobiosis in tardigrades - evidence for divergence in responses to dehydration. FEBS Journal 275:281–288. Abstract
Lapinski J, Tunnacliffe A. 2003. Anhydrobiosis without trehalose in bdelloid rotifers. FEBS Letters 553:387-90.