Artificial koi spawning

Countries outside of Japan often use hormone injections of gonadotropin (removed from the pituitary gland of wild carp) to bring on an almost instant spawning. This method is used widely throughout the worls for the mass production of fish for the table ie. salmon and trout. Nishikigoi breeders however, are not in agreement with this method of breeding koi as it is seen as a risk to their valuable broodstock. Also, their methods pruduce more than enough fry for then to econimically handle. In modern koi breeding microchipping may be used, this means that parent male and female fish can easily be identified within the breeding programme and ensuring that a specific variety will 'throw true'. This is a term used to describe the offspring from a particular spawning. Basically, if progeny are identical to the parent and have not produced any 'throw-backs' (fish varieties of unknown parentage and origin) they are deemed to have 'thrown true'. This can also be the case when cross-breeding to poduce a planned new variety.