I know tilapia are omnivorous, but what I saw today really surprised me. After I cull fish, I throw them back in the water for the remainder to eat. I usually leave right after, but today I stayed for about 15 minutes.

I saw several tilapia nibbling on the fish that I had just thrown into the water. After floating for probably 30 seconds, tilapia would swarm the fish, peck off all the scales and fins, and then interest would drop off dramatically. I even saw one as long as my forearm come up and eat a one inch fish whole.

All the tilapia were as fat as could be, so I'm not concerned about them being too hungry. I'm just curious as to whether or not this behavior is typical?

I have seen similar with my tilapia. I can only assume its a curiosity or territorial thing that goes on. Even if I add a few fish the same size as the tankfull of others, the new ones might get picked on. I find to help with this, I will net out the whole bunch and throw them in a bucket. Seems to disorient or upset the routine of them. I throw in the new ones, and dump the whole thing back into the tank.

they will take to opportunity to eat anything. mine eat dead fish and even steak fat I toss in the pond for them to eat.

Tilapia will eat other fish, but not expend calories going after anything but dead or injured fish....much like turtles.