| theres always the chance of hybrids,but it is very uncommon,alot of people keep both types together,including my self in an out door pit,i find the blotchys tend to stress the easterns,mind u i have a lot more blotcheds out there,i think the hybrid issue would be more a concern if u had a male of one type housed with a female of the other,and even that wont mean they will hybridise ,but its always a chance | 
