As long as you cut a piece of the mouth off when you cut it, they should live. On my local forum, a guy cut about 100 rics in half (a majority of them had multiple mouths, but some had only had one mouth) and he ended up with close to 200 healthy specimens. IMO, I would wait till it grew another mouth, but it can happen if it only has one mouth if you want to chance it. He had a very good success rate, but he did loose a few. Good luck in whatever you decide