And When Is It Just Right?

Yesterday I talked about one of my sixty gallon tanks and how it was too small for just six angels, because they had become aggressive.

I have a seventy gallon tank with six angels and they are very happy and peaceful. Why the difference?

I suspect the peaceful tank is due to the larger number of females in the tank. You can tell an adult female angelfish by her behavior; she is very peaceable and tends to stay by herself, just "standing" as it's called - hanging out and looking good. However, once she has begun to lay eggs, she can be as aggressive as the males while protecting her young.

In contrast, if you have a tank full of angels who are constantly fighting, it means you have a large number of males.

So when you're in the pet shop and you need to select an angel, how do you know what you're getting?

Most pet shops sell baby angels and it's impossible to tell what sex they are just by looking at their bodies. However, you can often tell by watching their behavior - and their size.

Males tend to be larger than the females.

When they think you're going to feed them, males will often nip at the other males - it's their way of establishing a pecking order. Watch the ones who nip and the ones they are nipping and avoid both if you want females. Male will very, very rarely if ever go after a female. Females will watch you attentively but they won't be attempting to run off the others as they gather to feed.