| In juvenile fish, determining sex is | | | | spawning, and should be closely |
| almost impossible. It is only when they | | | | observed. |
| begin to pair off that an opportunity | | | | It has been said that the male discus |
| arises to help in the determination of | | | | fish will tend to have a less intense |
| sex. Juvenile fish, both male and | | | | color and more pattern while the female |
| female, have a rounded dorsal fin, and | | | | tends to be more colorful but with |
| it is not until they begin to mature | | | | lesser pattern. I disagree, because too |
| that a difference can be detected. As it | | | | many variables are in place here, such |
| is never wise to excessively handle the | | | | as the health of the discus, the water |
| fish, close observation is in order to | | | | parameters, and feeding pattern. |
| aid the breeder. | | | | In an interesting article by Jeff |
| In Allnut Enterprises' King Discus | | | | Richard, he discusses an article from |
| Hatchery, for example, it is an easy | | | | Diskus Brief, a German publication, |
| process to determine who is who, as we | | | | which reports a very successful way of |
| have observed these fish for a while, | | | | determine sex of a discus by using |
| and can determine the sex of the pairs | | | | simple geometry. Jeff reports, and I |
| we own. This would be true in any | | | | quote: "Picture a discus facing to |
| hatchery. But to the uninitiated or | | | | your left ... you would be looking at |
| casual observer, this would not be easy | | | | its side. Find the Dorsal (Top) and Anal |
| to do. | | | | (bottom) fins and look where the fins |
| Some of the identifiers: The male will | | | | slope down toward the Caudal (tail) fin |
| have thicker lips to aid him in his | | | | ... make sure you're looking at the fins |
| fight to protect the female, and will be | | | | after they have curved back toward the |
| more aggressive. He will be larger than | | | | tail. The Dorsal and Anal Fins become |
| the female, his forehead is thicker, and | | | | (almost) straight after the fins curve |
| we have observed that if the discus are | | | | down (or up) toward the Caudal Fin ... |
| a bit shy, the male will have a tendency | | | | extend an imaginary line along this |
| to stay between the female and the | | | | straight section of the 2 fins back |
| observer. | | | | toward the tail which just touches the |
| The dorsal fin of the male will be | | | | Dorsal & Anal Fins past the Caudal |
| pointed, and the female's dorsal fin | | | | Fin. These two imaginary lines should |
| will be rounded. Note that in juvenile | | | | intersect behind the fish. The key to |
| discus, this is not apparent. | | | | sexing the fish is where the lines cross |
| The breeding tube of the female, between | | | | the Caudal fin. If they pass through the |
| the anus and anal fin, is broader and | | | | Caudal Fin, the fish is most likely a |
| rounder than the male, and will have a | | | | FEMALE. If they miss or just touch the |
| blunt tip. The male, in turn, has a | | | | Caudal Fin, then most likely it is a |
| smaller, sharper breeding tube. Be aware | | | | MALE." Thanks, Jeff! |
| that this is only evident during | | | | |