Being a characin I would imagine they are somewhat skittish in a smaller tank. This guy isn't skittish, but during feeding time he clears the way for the PBass, RTCs and Arowanas.
This guy isn't aggressive, but like I said, there are many horror stories of them disemboweling silver characin-like fish.
90% percent of the time he will just be swimming in place. Then he will usually move directly to the next spot he plans on doing that.
One more thing is, this one is pretty chubby and I have seen a lot of pictures of abnormally fat odoes. I believe Norbert has one, you can probably try asking him about his.