My petricola are fed last thing at night with frozen bloodworn 4 or 5 times a week, and on a daily basis with TetraTabimen tablets [which they love],TetraPrima granulated food [which is fairly small and sinks quickly],and every other day with either Tetra variety wafers or Ocean nutrition algae ...

I have 18 petricolas in a 100 gallon tank, and often find that either a single fish or a group of up to 4 or 5 will follow this behaviour. Mine will do this for several hours or a day or 2 and then stop for several days. Sometimes I will then hardly see any of them again till lights off.This ...