it's ok to put them together, i had a tank filled with different types, started with goldfish and ended up with all kinds. I believe the orange with stripes could be a clown loach, they are fun to watch if you have 3 or more. Just don't put guppies (the ones with fan tails) together with a irridescent shark (one of my sharks ate the guppie
) My goldfish, which i thought would die within days ended up surviving for 1 yr!) Have fun with you fishies, it can get addictive! lol