75 Gallon Tank If I feed my Oscar a goldfish, will he eat tank mates?

I know this is a crazy question, so let me start out at the beginning. I've had my 75 gallon tank about 2 years with 2 Oscars, 3 fire mouth cichlids, a pictus catfish, 1 peacock cichlid and my pleco. Yes I know I should have a bigger tank for my inhabitants but they're all very healthy and happy and I change the water often. I've never fed my Oscars live fish before. I woke up to find my Oscar eating my last baby pleco but I've never fed him live fish on purpose, besides live crickets worms and roaches. He gets along with all the other tank mates atm (as long as they do what he says ). My question is, if I start feeding him live fish like goldfish or guppies, will I be showing him it's okay to eat other fish, or will he already do this and he just doesn't want to eat his tank mates because I keep them well fed? I know once a dog attacks a cat and gets the taste of blood then they always say he will do it again. I'm wondering if I feed my Oscar a goldfish, will he try to do it again to his smaller tank mates because I told him it was ok? I've been able to train him to be nice to different fish and not eat them by showing my displeasure at him. Yes I know this sounds crazy but my Oscar is really smart and figures things out very quickly. If I get mad at him for bullying a fish and I show him I'm angry he stops doing it. Either that or I get his attention elsewhere but it always lasts a while before I have to yell again so I think he's learning. I don't want to teach him I think it's ok for him to eat smaller fish. Like I said crazy question. No haters please, I'm really curious.

 

I'm pretty sure if he's hungry and it fits in his mouth he'll eat them... No matter how much you yell at him!

 

If he's eating baby plecos, I think he already has a taste for fresh fish. I agree if it fits in his mouth, it's history. Sorry

 

Yeah, once the oscar is hungry enough, that fish gonna get ate more than likely. I always figure if i keep an oscar, gonna be a common pleco and thats about it.

 

Another thing to consider is if you frequently feed live food, it's possible the Oscar at some point can refuse pellets.

In my opinion, I think it's better to spend the money and get high quality food than feed live; less risk of disease and more nutritious. You can also get your Oscar to eat raw chopped up grocery store fish, shrimp, mussels, etc.

But if you want to feed live occasionally for entertainment purposes, I recommend quarantining those feeder fish first before feeding as it's not worth getting your prized fish sick.