One of my new rasboras has developed a peculiar lump near his mouth. It's white, round, and about 2mm in diameter. He appears to be in good condition, his fins show no damage, he has good color, and appears to be behaving normally. The lump didn't appear to cause him any problems at this morning's feeding.
This is my work tank and it's one month old. It's cycled. Current parameters are:
The tank gets a 30% water change about every 4 to 5 days, depending on when I get bored at work.
I've read through the stickied thread on diseases and nothing seems to match what I'm seeing. The lump appears to be smooth and round with none of the filamentous strands I'd expect from something like a fungus.
Yes, I realize that I should have quarantined these fish. However since this is my work tank and not my home and my QT tank was broken down I decided to add them straight away, I'm hoping I didn't really screw up.