Was thinking about buying a Vampire tetra and a reticulated ray for my tank, just wondering about the tank mates, which are a Albino oscar that actually hides from the other fish lol, a silver arowana, spotted gar, RTC, clown loach, BGK and african knife, and 3 birchirs, there are all young, just under 7-9" i heard stories of vampire tetras ripping apart tank mates and then some stories of them being very skittish and scared of your hand, also and whats the difference between a armatus and a vampire tetra or are they the same just named by different locations. thnx