Yes, and while you're figuring out the font thing
You have some issues in your aquarium with the fish species. The disappearance of smaller fish is due to one of these.
We have profiles of various fish, second tab from the left in the blue bar at the top will take you there, or you can click on shaded names in posts. Please have a look at the profiles for the Pictus Catfish and note that it is predatory, and should be in a group or it will likely not do well.
Clown loach, as kymmie said, also must be in a group, they have a social structure, but get too big for a 55g tank.
Red tailed shark will be aggressive to other bottom fish, sometimes highly so; it should not be kept with loaches and catfish.
Unless larger tanks are in the foreseeable future, you should consider returning some of these fish. Stress will occur to these fish and the others and this means health issues plaguing the tank.
Last but certainly not least...welcome to Tropical Fish Keeping forum.