What Gender are my Australian Rainbow Fish?

Hey, I have had a few rainbows in the past, and there are a few ways that you should combine to sex them as many times just one won't work
1. Coloration. Females tend to bee a lot more pale and bland in coloration whereas males can have more striking colors
2. Dorsal fin. females will have a shorter front dorsal males will have larger one, usually nearing or overlapping the second dorsal
3. Shape. When the are fully mature and then some, the males will become almost discus shaped (but not quite as exaggerated) and the females will tend to get longer and more streamlined.

take into account that these methods usually work better when the fish are mature and higher quality breed. Which if you plan on breeding them, will need to be a factor. Hope that helps!

also I wouldn't advise keeping corys with a ram. when the ram matures that might not be a good combination....

I have australian rainbowfish. The males are more colorful, and have the yellowish fins, whereas the females are not as colorful, and have reddish fins.