Fish injury?

[hb3133]

I purchased a Zebra Danio, from Wal-mart, about 10 days ago. I just noticed that its on his last leg. It looks like he has a injured mouth. It's mouth is wide open and its on the bottom of the tank. It is like his jaw is pried open. This particular fish has always been a great eater . I am new to the hobby and I am currently cycyling my 20 gallon tank, day 11. My levels are currently at:

pH= 7.4
amonia= 0.5ppm
nitrite= 0ppm
nitrate=0ppm

So, I am assuming that it is an injury, sickness from toxic levels or a unhealthy purchase. Any help would be greatly appreciated!

 

[talloulou]

Does the mouth look cotteny? Lying at the bottem of the tank with mouth open could be a symptom of amonia poisoning but it might also be columnaris. Both problems would cause loss of appetite. Amonia poisoning would probably cause red gills or red streaking in the body of the fish. Is the one Danio the only fish in the tank? Have you recently done a water change? If so it's possible that the amonia was actually higher than 0.5 at some point.

Anyway I would do a 50% water change daily. IMO the fish may not make it through the cycle since you are at the very early stages of the cycle and the fish is already stressed. It could be that the fish has columnaris/cottenmouth and the amonia present in the tank is exacerbating this. Columnaris also tends to be contagious so if there are other fish in the tank they could be at risk and start to fall like dominos.

If you suspect the Columnaris then it might be a good idea to use aquarium salt.

Either way definitely do daily 50% water changes.

Here is a site that may help you diagnose your fish better

http://freshaquarium.about.com/od/diseaseprofiles/index_a.htm

 

[hb3133]

Thanks for the quick response. I did a 20% water change yesterday after getting an amonia reading of >0.75ppm but <1.0ppm. I have 4 Harlequin Rasboras that seem to be doing well. The Rasboras were purchased at the local fish store. I just checked the Zebra and its doesn't look like columnaris. I am assuming the Zebra is not handling the amonia as well as the Harlequins.

 

[talloulou]

I read your other post and I see that you have other fish. It might be a good idea to take this danio out of the tank and put it in a hospitable tank or rubbermaid container and treat with a salt bath. If this fish has columnaris or some other contagious disease the other fish will have a much harder time making it through your cycle. Also you have alot of fish and you are in the early stages of your cycle. I would try to get some bio spira to speed up your tanks cycle. Also if you know anyone else who has a fish tank try to get some of their gravel or filter media for your tank. This will also greatly speed up your tank. Sometimes local fish stores are willing to give you some gravel or filter media. And be sure to do at least 50% water changes daily. But do not vacumn your gravel while the tank is cycling.

 

[hb3133]

I have been told many different numbers as far as partial water changes. Some people seay 10%, others 20% and then a few 50%. I a little concerned about the great range in percentages. I am assuming 50% is safe?

 

[talloulou]

IMO you can never provide your fish enough fresh water. So I believe water changes should be done as much as you feel like doing them and I don't believe you can ever do to much. Most people tend to like small partial water changes 10-25% because they are easy to do without affecting the tanks temperature and you don't run the risk of altering the pH or anything too much with small changes. However I do large water changes all the time and I believe my fish are healthier because of it. If you suddenly do a large water change on a tank with old tank syndrome the fish could definitely be badly affected because their bodies have grown accustomed to living in old water conditions. However on a new tank this won't happen. And I feel frequent water changes is definitely a good habit to develop early on. For a tank that is cycling I would definitly do 50% daily. This should prevent you from losing fish. And the more fresh water they have the less stressed they will be as well.