I used it today for the latter. I suspect this won’t work well for some fry, but it does great for shell dwellers. Shellies and their offspring tend to hug the substrate more than many other cichlid species. In fact, my Telmatochromis sp. “shell dweller” fry stay attached to the bottom like glue. The flat bottom of the scoop makes it really easy to run it across the substrate (or underneath the substrate if you’re scooping it out). Also, the scoop is clear, which may be less threatening to the fry.
During tank maintenance this afternoon, it was time to remove the rock-work in the half of the tank where my Telmats reside (my 75g Tanganyikan community tank). A little over a month ago, I set up a fry/grow-out tank. I had already moved some fry that I caught, but had many more to catch in the 75g. Rather than continuing to rely on moving the fry in shells, like I had been doing, I decided to use the scoop. It worked phenomenally well. In the span of 10 minutes, I had caught nearly 10 fry (~ 1/4 inch +). There are a few more still in the 75g that I tried to catch but was unsuccessful. A task for another day.