There are some subtle differences that an experienced angelfish breeder can use to help identify mature males and females. Some angelfish enthusiasts say that the angle of the anal fin in relation to the belly of the angelfish, will identify the sex. Others say that some male angels may have a hump on the crown and some may be larger than the females. There seems to be too many ways of telling them apart, but none seem to be 100% correct. These differences do not exist on immature angelfish, all of the time. Therefore, the only sure way to tell the difference between mature males from mature females is to examine the breeding tubes during spawning. The female's breeding tube is wider and more blunt than the male's.