FX is any offspring after F-1 or any cross between 2 parents who are not pure. Example a HBG cross with a BG , or a GSF cross with a HBG or a cross where one or both parents is not pure like a fish that is 75% BG and 25% GSF with another fish.

Stated another way any fish other than a pure strain or an F-1 cross (which is the cross from 2 pure parents (BG X GSF = an F-1 HBG).

Last edited by ewest; 09/05/13 10:37 PM.