Daphnia/shrimp & brown Crypt. wendtii

Do daphnia or freshwater shrimps feed on crypts? Here is the
situation.

I had a 40 liter plant tank with otos and a few cherry barbs for
color. The tank had been up and running for a year without any new
fish or plants added. The food I fed to the fish included Tetra flake
and tabi min. No live food. Nice algae coating on one side for the
otos. 3 weeks ago, I noticed small specks which I took for "fry" in
the tank. With only the cherry barbs and otos in the tank I suspected
it would be fry from these fish. Rather than try to siphon out the
tiny "fry", I moved the cherry barbs to the community tank hoping to
let the "fry" grow.

When the "fry" grew to roughly 2-3 mm, it was plain to see they were
not fish fry at all. Looked more like tiny shrimp with the many legs.
They sometimes crawl like insects on the glass and flee to the bottom
and try to embed themselves in the gravel when the lights go on. Fine
I thought. I'll let them grow and use them as live food for the
community tank. I had a nice grove of 5-6 brown crypt. wendtii. Now
the crypts are virtually wiped out with the little buggers hanging on
the edges of the nearly defoliated crypts. Little over one year's
worth of growth gone in less two weeks. I guess that the cherry barbs
were keeping these plant munchers under control but I've never noticed
the things until this past August.

1) So where did I get these "shrimp" if they are really shrimp. Eggs
in the dry food?

2) Should I chance feeding them to the fish in the community tank? I
have crypts in there too and wouldn't want those plants to be wiped
out too if these "shrimp" should take hold.

Thanks.