oscar cichlid growth water

Hello! I want to know the names of these fishes. So, that i can check the compatibility of these fishes with my current aquarium fishes.

I have an Oscar which I rescued from a guy off Craigslist who had him in a 50 gallon tank with a bunch of other fish.. About 10-15. He was sick, near death when I took him. I brought him home and put him in my 100 gal and nursed him back to health. Honestly didn't think he was going to make it...