Sexing Goldfish (Ikan ni Jantan ke Betina??)

Salam & Morning,,,

Many not know how to sexing goldfish. Even ornamental shop staffs and owner confuse to differentiate male or female of the fish when i asked them. Sexing goldfish is very difficult before they reach maturity. Sometimes people can tell by looking at the shape of the Vent. Females may have rounder convex vents while males have thinner concave vents. The pectoral fin of males may be rather thick and stiff (compared to those of female goldfish) and with a more pronounced outer ray. Some people also believe that male goldfish have longer pectoral fins than do female goldfish.

First, we should know about Internal and external features of Goldfish:

The following pictures will help you determine the sex of your mature goldfish.

Breeding Stars or Breeding Turbercles

Male goldfish with breeding stars/ tubercles on their gill cover (Operculum) and along the first ray of their pectoral fins when they reach sexual maturity.

Male Goldfish

This picture of my Mykroll's red capped orandas shows the stars and thickening of the pectoral fin of the male (Compared with the female). The female's body is also more rounded than the male's.

Vent

(Male)

When goldfish are ready to breed you can observe changes to their vent area. Below are pictures showing the vents of two mature male. The vent is longer and is indented (concave). This is a lot easier to observe on a mature fish who is ready to spawn.

(Female)

Below are pictures showing the vents of two mature female goldfish. The female vent is not as long but it is protruded (Convex).

Behavioral Changes

It is the female that really "controls" the breeding. A female goldfish (not ready to breed yet) will send out pheromones (a types of steroid) which will encourage males to produce the milt. When the female is ready to breed she will release another type of pheromone that stimulates sexual behavior in the male. The male will react by checking out the females, nudging them in the vent area as you can see on this picture. Males may exhibit this behavior before the females are ready well, but it will be fair intense once the female is prepared to prepared to spawn. Once spawning starts the males will chase and bump the female until she release her eggs.

The Result

The female should release eggs that will look like these.

The Goldfish in tanks will eat the eggs, so if you want to raise fry you will either have to remove the eggs or the parents. Here is picture of a 19 days old goldfish fry.

Happy sexing and breeding Goldfish..