Tropheus fry love snails! Especially snail eggs. You can see that gooey spotted mass on the back of the container. These snails have been busy.
I’m certain that snails are part of their diet in the lake. Very high protein for a vegetarian fish. I’m sure they will grow out fast and strong with the added snails. Plus they do a pretty good job of cleaning the glass. Too bad they don’t last long in the adult tanks.