R
Surface tension. Tap them, they'll sink.
Puttem in the dark. There's O2 in that water to support tails. They should be fine tomorrow.
I did tap the blueberry last night and they came back to the top, kind of weird, I think it may just be a dirty glass LOL. They have been in the dark for a little over 24 hours, the cabinet over the stove never lets me down