I have had common pleco's (nothing fancy) - but it is about 6" long and defends well against the varieties of Africans. I also have rubber and clown pleco's but these are generally smaller (max 4" ish). I have not seen my clown pleco in my 30G with Africans for over a month. I know it is still there because I am rebuilding it and I had to move him. But it is normal for him to hide along with the cichlids in the tunnels that I have for them.