the juvenile photo looks like a striata, and the more recnt one,,, cant make it out... but it could pass for a micopeltes or both???
but micropeltes have a very distinct torpedo head, or like a shark, very lateral. and striatas head looks like a spoon, with a spoon posture.
my striata is a psycho. but what has been said earlier, yeah it sounds like it's claimed the tank... maybe you should give it an arse woopn?
striata more vicious than micopeletes? good question. pound for pound, maybe...
i've fished for both in the jungles here, and you dont see striatas biting fish in halves, they just dont get big enough... but a mature average size micropeltes is like a 3lbs-er, with razor sharp teeth, that will strike hard at a variation of top waters, and their sheer size turns monofiliment into confetti..
tough call, to say which one is more aggressive. i've never had a mature micopeltes in captivity... yet.