When I turned on the lights today I found one of my Panda Cories on the floor of the tank with a wound on his side. I'm assuming its a wound, but I'm not sure if it could be disease related or not. A while ago I had been having trouble with internal parasites, could this be related to that? Or is it something different? Here is a picture:
One thing with this picture, that yellow is just the camera playing tricks, its actually all red...I don't know why the photo turned out like that
Shortly after this picture was taken, he died.
The tank is 75 gallons. I just did a round of testing, Ammonia is 0 ppm, Nitrites is 0 ppm, Nitrates are between 20 ppm and 40 ppm, which is really high for this tank (I've been feeding some brine shrimp I've been hatching recently and am still getting used to amounts) pH is 6.6, temperature is 76 degrees. It is home to 10 Panda Cories (8 adults and 2 fry, not counting the recently deceased), 11 Harlequin Rasboras & 1 Espei Rasbora, 12 Gold Tetras, 11 Dwarf Neon Rainbows, 1 male Bristlenose Pleco, and 1 Neon Tetra fry. I'm going to do a partial water change to get the Nitrates down now, and I also just finished a head count and observation of all the other fish - everyone seems healthy, and no one else has any wounds or marks or anything unusual about them, and everyone seems to be behaving in a typical, active manner.
For detailed information about the sickness I've been dealing with before this check the tank log. I did recently lose a Rainbow, but she seemed to have died from complications of the previous parasite infection (she was very badly infected and I had been expecting her to die for weeks because I thought she was too far gone when I treated everyone a month ago). This little guy, however, was not showing any sign of illness until now, and his wound was nothing like what the Rainbow was exhibiting.
If anyone has an idea of what could be going on please let me know.