Angelfish Gender

I was not sure this would work, but apparently it has. The drawings below are from a very old pamphlet about angelfish. The only sure way to sex an angelfish is by looking at their spawning tubes, which are deployed only when they spawn. Some people can make pretty accurate guesses by looking at other characteristics, so here are a few of them. At the time the pamphlet was published, silver angelfish were about the only aquarium species.