Another bites the dust

This morning I found another one of my fish dead on the floor next to the fish tank. It had jumped out of the tank overnight, this is the second fish that has done this. The first one I managed to save because I found it just in time, I was able to put it back in the water only to have it died on me days later.

But this time it must've jumped out much earlier cause by the time I saw it it was already lifeless. Comets are fast swimmers and can leap out of the water so easily. I need to lower the water level or cover up that opening where they tend to jump out from.