I have dwarf ancistrus. They are adorable, about the same size as my otos. I've got them in 4 tanks, with various types/sizes of fish. They're a lot like otos, zip around cleaning things all day. They don't bother plants although they do clean the sword leaves religiously. 
They also don't bother any fish or shrimp.
Mine have a nice white stripe on their tails, I don't know if they all do though.
They also don't bother any fish or shrimp.Mine have a nice white stripe on their tails, I don't know if they all do though.
