Tail fin partially torn off

Question
A baby pond fish that we rescued had his tail partially ripped off by a rogue crayfish (who is now gone from the tank, my son brought it home from the pet shop without asking). Is there a chance the tail will grow back do you know? It was not bleeding or anything, but he was a fantail and the lower part of the tail was ripped off completely (not all the way down to the body though). Also, he just went through a period where he was a silver color, got black on the top half of him (NOT ammonia related), then the black is going away and he is orange. I know color change is normal, but I never saw it happen like it did, and didn't know if it was normal or not. The fish is acting fine (eating, swimming, begging, etc.) so I don't think there are any illnesses, and I've been watching the tail fin closely for any signs of infection, but there hasn't been any.  Any thoughts on this?  Thanks in advance.

Answer
Hi Trish
Not sure what type of fish that is, but it's common for a lot of fish to change colors.  Especially if it is a juvenile, it may be going into it's adult colors.  As long as the water quality is good-no ammonia or nitrites, and nitrates under 20 ppm, should be fine.

For the tail, yes it most likely will grow back.  Your best bet-again with the water quality, keep that really good to help prevent infections and such.  You could also try using some MelaFix-it's a natural herbal antibacterial remedy, works great for injuries to tails and fins.  It won't harm any of the fish, plants, beneficial bacteria, completely safe to use in the tank.  Pet store should have it, or if you're in the US, I've been seeing it at Walmart in the pet/fish section.

Hope that helps and good luck!  Let me know if you have more questions.

Christy