Bloody fin.. Help ??

[sabrinarichard]

Here as two photos of the same zebra danio... Sooo.. What's up with him ? He seems to gave a bloody fin.. I added yesterday a new male guppy who died during the night.. (the road was ruff we probably stressed him out ) but he had nothing on his body! I isolated the danio in a hospital tank in case it's something else tank a little fighting wound.. (He was just in the glass for a picture)
Any opinions ??
Thanks!!

 

[sabrinarichard]

Here is a better picture

 

[sabrinarichard]

He seems to have a spot of blood just under the fin on his scales