Fish with blood streak above fin!

[mrseigel]

Hi all,
I posted earlier but I recently had 4 neon green rasboras shipped to me. 2 have died and now one is struggling to swim with a red streak of blood above his ventral fin (see pictures)
I tested water with the following results:
Ph =7.2
Ammonia = 0
Nitrite = 0
Nitrate = 10ppm
KH = 3
GH = 7
Any ideas?!

 

[GaryE]

I can see nothing in those shots, but blood streaks are usually bacterial septicemia infections. I can suggest no treatments.