[Zephyr]

One of my zebra danios has been staying away from the main school. No clamped fins, but I noticed that it has a bit of a torn anal fin.
Also, it looks a bit fat.
Is it preparing to drop eggs, or is it just sick? If sick, with what?

 

[bettababy]

It may be a gravid female, and the males are probably spending plenty of time chasing her. I would suggest keeping an eye open for other symptoms, but if there is nothing more, I wouldn't be real concerned. If you notice the other danios harrassing her too much, adding another female or 2 (if your stocking levels allow for it), along with some floating plants for extra shelter for her.