Yikes, yeah, you need to separate them.
Aside from the fact that they are completely separate species, Chinese hamsters are more territorial than Russians. So they would probably fight indefinitely. Chinese hamsters don't like to share. Introductions probably would not have helped anyway.
Russian hamsters can sometimes live together, but usually only with littermates, and even then you often have to separate them eventually. They are communal in the wild, but in a cage it is a different story because they don't have the option of running away.
It might be possible to get two different species of hamsters to live together, but every time I have seen it tried it has not ended well. A local pet store here in Denver tried to mix Syrians and Russians together...I came back a few days later and one of the Russian hamsters was missing an eye. Just sayin...
Last edited by pruje; 02-01-2010 at 04:40 PM.