Strange Fry Behaviour

Fishing the Trent last summer, I watched the fry repeatedly being attacked by either perch or chub, right in the edge.

These fry (couldn't tell what they were, possibly chub) were scattering when they were attacked but lots of them were leaping clear our of the water, to land in the gravel sourrounding the edge of the water. They would lie there for a few seconds until the commotion was over, then flip themselves repeatedly until they bounced back into the river.

I watched this for hours and am absolutely convinced that these fry knew just what they were doing. When I tried to approach them to see what they were they would flip back in before I got to them. Sometimes they would stay grounded for 30 seconds or more.

Has anyone else witnessed this behaviour?

Yes, many times.

Most of this is caused by perch, and they are not always big ones either.

Good job there weren't any herons about.Did any of the fry remain stranded?

This was also happening on this years Trent fish-in and I've seen it during the summer on the Ribble, but it's mainly trout and chub doing the chasing.
I personally don't think this is strategy adopted by the fry, but just the consequence of fleeing from being eaten.