Danio w/ pop-eye

[jeremyh81]

Earlier this month, I had to leave town for work on very short notice. I left on a Wednesday, came home the following Sunday to do water changes, add vacation feeders to my 3 tanks, and get enough clothes for another week on the road.

When I got back on Saturday, I found that one of the zebra danios in the 26 bowfront had developed pop-eye. After some reading, I thought it was from poor water quality because another danio seemed bloated, and I thought that was dropsy. So I immediately did a 40-50% water change and added the proper amount of salt.

Now, 2 weeks later, the "bloated" danio still has a big belly, so I'm hoping it isn't diseased. The danio w/ pop-eye no longer has a protruding eye, but now has what looks to be skin where the eye is or should be.

I haven't tried to net the fish into a specimen container just because the plants in the tank are so large now, it would be impossible to catch the fish without uprooting the wisterias.

The danio is otherwise, seemingly strees-free. It is eating and swims throughout the tank. Sometimes, it will swim in circles in the direction of the good eye or hang out in a back corner where the good eye can see all.

Does anyone have any theories here? I know it's hard without pictures, but I'm not going to stress this little guy anymore than I need to until it shows signs of stress.

[jeremyh81]

It's very possible the "bloated" one is a female, since that's how you sex danios: when viewing from the side, males are a slender, torpedo shape, where females have a rounder belly and a usually smaller (like this one).

From what I barely remember from reading about breeding danios a few months ago, the water temp needs to be around 78 (tank is currently about 77) and the water level should be lowered. They also choose their partners and stick with one for life. One part I remember about partner selection is that the female prefers a male that is larger than herself. There's also the male to female ratio that comes into play. Once paired, the male will nudge the female near the anal fins to prompt her to spread eggs anywhere and everywhere. It's very likely the one w/ the large belly is a female full of eggs.

I'm not interested in breeding them since they're so common and eat their own eggs/fry. Also, I may have too many males competing for her. So she may be ready to lay, but hasn't chosen a mate yet. I'll read more and see if I can just get her to spread the eggs, which would give many of the fish some good, "live" food.

As for the diseases "dropsy" and "pop-eye", they are bacterial infections usually brought on by either a pre-existing condition, poor water quality, or the bacteria introduced by an outside source. But pop-eye has an additional cause: injury. Just look at pictures of pop-eye - seeing that in your tank would make one worry.

Since I've had these danios for about 4 months and the rest of the community is fine, poor water quality or injury are the most plausible causes.

Danios are also considered schooling fish, but mine seem to roam the tank independently. Sometimes they'll chase each other, either playing or possibly being territorial. Being a smaller tank and the danios out number the other species, they may just think that they're safe while not staying in a tight group.

I'm just wondering what happened to this poor guy's eye. Is it healing, or should I name him "Popeye" in sympathy and to reflect the strength of my favorite childhood cartoon character, who usually only had one eye open?

[angel]

No they don't. And left untreated, the fish will die. Not because of the inflamed eye, but because of the condition that caused it. Popeye isn't really the problem, it's the symptom.

[angel]

Ok then. Sure! The eye will grow back and it might even be a different color than it was! Maybe sapphire blue! And the one that popped out you can take out and petrify it and it's a bead!

Cheery. Not true, but cheery just the same.