I have a new pair of clown plecos, and need to reshape the tank a little bit to give them more hiding places. They're still small (about two inches) and have only been in the tank about a week, but neither one has really claimed a permanent territory.
How will they use the "pleco caves" that are available? Once they've settled in and have more options to choose from, will they each pick a space and stick with it over time, or will they just grab the first convenient hiding place every day?
I have never seen plecos claiming territory permanently. That being said, fishes have personality too and the behavior will surely be different for different fishes. Like a lot of species, plecos love to remain in some kind of shelter i.e near the filter, under a wood piece/decor etc. It is always a good idea to provide more hiding places than needed, fishes will choose the place they feel safest leaving the open ones behind. But as they settle in, they'll claim more of the open space and can be seen swimming everywhere in the tank. Not sure if you have any other species in the tank, if so, make sure they don't disturb the plecos since they're small in size, any fish might want a piece of them :)
Plecos only claim territory when they are spawning or the male is fanning eggs. Overall, they are generally nomadic and as long as there is a place for them to hide, they'll be fine (not stressed).
A good strategy for fish that are being picked on, is to remove all the fish, reorganize the tank and re-release the fish. This will cause any established territories to be removed and the pecking order re-established. In general, this would mean reorganizing the tank (with no spawning fish) won't cause too much stress.
