Big fish are not for pretty tanks! If it is a big fish?
If you like a fish so much to be moved by its physical appearance the setting need only be suitable for the fish, heavy rock and large wood pieces tend to stay put, bigger plants seem to fare better, tough leaved things like Anubias tend to be left alone.
Once the tank has been arranged by the fish it normally stays that way, lighter substrates typically end up washed into the corners, something to bear in mind around the filter inlet. Sand is not filter friendly!
These fish or more correctly, large sized Loricariidae, need a lot of additional food!
I'm not sure this is a natural line of plec, I think it may be line bred or similar to long tail versions of things like platy.
(It is natural but not true to form)
Most likely some type of hypostomus, how big was it? They are sometimes difficult to identify as there are a few similar looking but different species.
H. Commersoni looks similar but I don't think it's that.
Much smaller species,
Ancistrus long fin, Ancistrus Temminckii? That's old/small enough to have been line bred.