angel fish bacteria?

[videokev]

we just bought an angel fish on saturday one of the fish that was already in the tank bit his fins pretty good this is nott the first time hes done this now the agel is growing what looks like mold on the wound areas any ideas on what this is and treatment theres a picture attached its not great but it might help

[Blinky]

Is the growth cotton-like? If it looks like cotton wool, it could be a fungal infection. Otherwise it's most likely bacteria. It's common for bacteria/fungus to attack the site of a wound, especially if the fish is weakened by stress.
Angels are territorial; the angel you already had likely considers this new angel an intruder on his turf and probably won't ever accept it. You need to separate them - it would be best to use a hospital tank (you can get a 10g tank, heater and sponge filter pretty cheap if you don't have a HT already).
Take a look online (you could try www.fishyfarmacy.com) to try and identify exactly what type of infection your fish has, but try not to delay - the sooner you treat this the more likely it is that the fish will recover.
A quiet hospital tank, frequent (daily is best - sick fish really benefit from super clean water) water changes and some antibacterial/antifungal meds are the best things you can do for him at this point.
Good luck, I hope you manage to save him.

[beviking]

Good advice from Blinky. 99 out of 100 times I'll bet on bacteria. Similar appearance, that's why you can get a treatment for fungus/bacteria in one bottle. It looks like fungus but its a bacteria, and some meds work on both too. Columnaris bacteria in particular, grows in mounds or haystacks under magnification but to the naked eye it looks fuzzy like fungus. This particular bugger can cause "tail-rot", "mouth fungus", small external spots or cover larger patches, and can become an internal infection too.
Luckily, the syptoms are evident b4 the fish is too weak (most of the time) to pull through and treatments are effective against it.
Good luck.