Six species of
Branchinecta make up about half of Alberta's anostracans, which is surprising. What I know of
B.gigas here is that it's found in larger prairie lakes seasonally, appearing early in the season before salinities change. It's also a predator, feeding on smaller anostracans like other species of
Branchinecta. You likely have a number of species in your neighborhood [hmmm...
B.potassa..., probably
B.readingi...]
Aquatic Invertebrates of Alberta
Atlas of Alberta Lakes
The tadpole shrimp I had seem in past were all in deep prairie or parkland ponds, which likely didn't freeze solid. They could have been
Lepidurus or
Triops. The ones I found last year were
Lepidurus, though I'd have to double check which species. What was odd, was not only were there TONS of them, but the water appeared to be shallow and flowing, in what was likely a shallow marsh connected to the upper reachs of a river near the continental divide. Not exactly the warm and temporary "vernal pools" they're expected from. In the back yard [west side] in a deep Rubbermaid bin full of aquatic moss and rainwater, they survived and bred. In winter, the bin was only a few inches of water, plus moss, frozen solid for parts of the season.
If I still lived in Yellowknife, I could probably harvest and export
B.paludosa [presumptive ID 35 years after the fact], given that they swarmed in every water-filled crack in the Canadian Shield. That may be the same species common in sloughs here, but with more than a dozen species possible, I simply haven't sat down with the microscope to do it, much less try to culture them.