Very few of the inter-speci¢c and inter-generic
hybrids of salmonids and cyprinids have any farming
or restocking potential because of their low viability
or inferior performance with respect to the parental
species (Purdom 1993). Hybridization between rainbow
trout (Oncorhynchus mykiss) and brown trout
(Salmo trutta) was studied by Blanc (2003), Blanc
and Maunas (2005) who reported poor hatching rate
and survival. Allotriploidization may produce a viable
hybrid (Arai 1988;Yamano,Yamaha & Yamazaki
1988).