I've found it's best to assume that if your fish is from a species that is known to jump, just assume that he will try it at some point in his life and plan accordingly. I recently lost my blue spotted jawfish to jumping; he made it out of a minute crack in the screens that I was using to cover the tank. I'd had him for two years. I will not be getting another one until I build a full canopy to keep him in. And while the mandarins I've known are not typically jumpers, they are capable of surprising bursts of speed and would sometimes jump out of the water if startled. Hope this helps!