They could. I normally pull eggs and hatch artificially, but I just had a cacatuoides female hatch a brood that I left with her. She put the clutch on the inside wall of a flowerpot that contained gravel and a plant. When she moved the hatched fry, she put them on the gravel on the other side of the pot, just barely at the edge of my view. I could see their reddish bellies on the gravel. When I checked a few days later, the fry were gone, but she was still showing some slight protective behavior. I normally experience egg/fry eating, which is what I think happened here. But certainly, loss into the gravel is a possibility. If you give your fish more cave-like spots in your tank (like flower pots laid on their side), your female will much more likely move the fry there, where there is no danger of loss into the gravel. It also makes them easier to grab by siphon if you want to raise them artificially. TOM