I've had a sun/eclipse catfish (Horabagrus brachysoma) for a little while and he's a good 6" long now. Usually he hides during the day but sometimes I catch him doing "aerobics". There is a log branch that extends to the side of the tank, creating a little clearance between it and the gravel. I can usually find him swimming in circles around the branch: goes underneath it, swims up, rotates, goes down the otherside and back under again. He'll do this for several minutes.
Could this be stress, boredom, or is he just eccentric?
Could this be stress, boredom, or is he just eccentric?