Koi Vents

[Russell Peters]

Koi Vents
It can be difficult to determine the sex of Koi sometimes. There are many ways to help you with this but sometimes, even with all of these things, it can still be difficult, even for Japnese breeders.

In males you will find that they can have "sandpaper" like bumps on their cheek plates. The leading ray of their pecs is usually bigger but not always. They also will have very small bumps on the leading ray of their pecs. The Japanese breeders will someting pour a small amount of water over their pecs to see if they see the bumps. They tend to have a longer, more slender body and their bellies tend to be firm. Their vent shape is different than females.

In females you will find that their cheek plates are smooth although a young, or undeveloped male, will also have smooth cheek plates. Females tend to have a more robust body shape and their bellies are soft. Their vent shape is much different than males.

[Russell Peters]

Female Vent
In the female Koi the vent will have two distinct features. #1 is the upper part and when the vent area is squeezed it will bulge and puff up. You will see a small hole in the center of this area. #2 is the lower area and is a larger opening. Both of these areas combined create a T shape.

[Russell Peters]

Male Vent
On the male vent you will find that it is more of a circle in shape and looks more concave. One thing a male Koi will have that a female Koi will never have is milt.