These may be the most plentiful fish caught for sport in Kootenay Lake.
That is just a speculation as I am neither fisherman nor ichthyologist. Nevertheless, small children wading in the shallows catch copious quantities in buckets and fishermen collect them for bait.
When a child, I called all of these tiny fish, minnows. Yet, many of these show signs of parr marks, which suggests that some of these are the fry of salmonoid species.