Please understand,
we cannot guarantee the sex of the Koi even though we use our very best judgment with the expertise and experience we have.
We try to check the signs and indication of sex, but some Koi are too young, making it very difficult to distinguish between male or female.
This is why even the breeders are not always accurate on the sex of their Koi.
Although we measure koi upon registration,
the size of koi may differ when growing on the farm after they are registered (date of registration is in the item number)
the size of koi may also vary if measure out of water and is dead.
Fluid from the body will evaporate causing change in body composition therefore shrinking.