fixing specific traits in convicts

[yourmylunch]

so i have this male convict wich has extremely long fins
and i want to make babies that will have that trait but i don't know where to start
i have bread convicts for a long time but just as feeders
and the babies from one nice male i had never looked as good as he did
genetics has bean one area i havn't had a good chance to read up on
any advice from the experts

 

[bshockstubb]

lets say you breed your long finned mail and a reg. finned female

long fins are most likely a recessive gene so whatever amount of babies have this trait(most likely 1/4) then take those and breed them with others.
until you get a pure breeding starin of long tailed cons.

it takes a while but where do you think all of these varities come from?