The fish ate all of the first leaves, including the floater that was just emerging. Disgusted, I moved it out of the culture tank into one of my tropical nursery tanks (which don't contain fish). I don't know what makes fish, which have never tasted the baby waterlilies before, to one day eat all of one of them.
I'm going to go back to putting screens around my seedlings and starts.
This plant's pretty tough, though, and pumped out new leaves in quick succession. I fertilized it a couple weeks ago. It now has five floaters, and they're getting more and more prickly. I'm going to move it to a sunnier location tomorrow, and decide then whether it should be potted up. No fish yet, though, until all of the leaves have spikes on them. This is the only plant that germinated from my three seeds this spring, and I don't want to lose it.
The textured pads of the euryale from the pot on the right are quite different from those of the tropical water lily in the pot on the left, even at this stage when they're not fully round yet.