It may sound crazy, right? But I captured these pics and a video of a show tank in the Dallas Worldwide Aquarium in which an asian red arowana was kept with hundreds of cardinal tetra, a few plecos, and a pair of Thorichthys elioti guarding a brood of fry. I do not know how big the tank was, but judging from the size of the arowana in comparison to the tank, it must be over 800 gal. The arowana was gliding gracefully among the cardinals, and I did not observe any predation. I can't imagine the craziness of mixing fish like this, particularly in a public aquarium. The pics and video were taken many years ago when I visited Dallas, but still puzzled me so I made a youtube for sharing. I wonder if the tank is still there. It was located in the auditorium, not the main display tanks area.
[video=youtube;6AK9WfyTffk]http://www.youtube.com/watch?feature=player_embedded&v=6AK9WfyTffk[/video]
[video=youtube;6AK9WfyTffk]http://www.youtube.com/watch?feature=player_embedded&v=6AK9WfyTffk[/video]