One of the biggest problems with discus growers is "How do I determine the gender of my fish?" There are very few easily identifiable identifiers in the process. Here, we will discuss some of the methods used by top breeders.
In juvenile fish, it is almost impossible to determine sexual behavior. Only when they start pairing can they have the opportunity to help determine gender. Juvenile fish, whether male or female, have a round dorsal fin until they mature to find the difference. Because it is unwise to over-treat the fish, careful observation is to help the breeder.
At Allnut Enterprises' for example, the King Discus Hatchery, this is a simple process to determine who is who, because we have observed these fish for a while and can determine the gender we have. This is true in any hatchery. But for unfamiliar or casual observers, this is not easy.
Some identifiers: Men will have thicker lips to help him protect women's struggles and will be more active. He will be bigger than a woman and have a thicker forehead. We have observed that if the discus is a bit shy, the man will remain nervous between the woman and the observer.
The male dorsal fin will be pointed and the female dorsal fin will be round. Please note that this is not obvious in teen discus.
The female reproductive tube between the anus and the anal fin is wider and rounder than the male and has a blunt tip. In turn, males have a smaller, sharper breeding tube. Please note that this is only apparent during spawning and should be closely observed.
It is said that male discus fish tend to have fewer colors and more patterns, while women tend to have more colors but fewer patterns. I disagree because there are too many variables, such as the health of the discus, the water parameters and the feeding method.
In an interesting article by Jeff Richard [http://www.aquaworldnet.com/dbws/sexingdiscus.shtml], he discusses an article by the German publication Diskus Brief, which reports a gender determination of discus. Very successful method. By using simple geometry. Jeff reports, I quote: "Imagine the discus on your left… you will look at the side of it." Fins… make sure you bend backwards and look at the fins down the fins After bending [or up] toward the caudal fin, the dorsal fin and anal fin become [almost] straight… along the straight line of the two fins, extending back to the imaginary line to the tail, just touching the dorsal fin and the anal fin through the caudal fin. These two imaginary lines should intersect at the back of the fish, if the gender of the fish is the place where the line passes through the caudal fin. If they pass through the caudal fin, the fish is likely to be a woman. If they missed or just touch the caudal fin, then it is likely to be male. "Thank you, Jeff!
Sexual discus is difficult at best. The easiest way is to make a set of at least six to eight discus and then pair them when they are ready. Seeing this situation is a beautiful sight and makes this hobby very valuable.