Sexing koi?

[Koikeeper99]

Anyone know how to sex koi? I have an idea because I read females fins are more rounded while males are more rectangular is this correct or how do you guys/gals tell?

 

[bettaowner]

Male koi will have rough white bumps on the gills during the breeding season.

 

[Koikeeper99]

Male koi will have rough white bumps on the gills during the breeding season.

When is "breeding season " typically?

 

[bettaowner]

Breeding season is usually in the winter or spring

 

[jlk]

Sexing koi is pretty similar to goldfish- its very difficult until they reach sexual maturity and even then, it is not easy. Males will develop classic breeding tubercles on their gill plates and pectoral fins when they are in ideal breeding condition. Females generally tend to be a bit rounder or even lopsided. You can also try to vent mature males and females. Behavior can be a great indicator as well. Breeding season is typically in the spring when the pond temperature warms and food becomes abundant unless you live somewhere that is temperate year round.

Heres a decent article on sexing koi and goldfish:

http://www.raingarden.us/sexingkoiandgoldfish.pdf

 

[Koikeeper99]

Alright thanks!