Need help：Pygocentrus nattereri‘s gills roll up

[Trevor033911]

Hey everyone. There are around 20 Pygocentrus nattereri in my bowl. And I feed them from they are very small. Recently I found they may have some gills problem. Firstly just 1 fish. Now they are around 4 fishes got this problem. The water quality is pertty good. No ammonia no nitrite. I just don't know why they got this diease. I really love these fish and feed them boiled shrimp, codfish, squid etc. But I changed the water not usually so the nitrate may a little bit high. So how to treat them. The fishbowl is 43 gallon with 6 gallon bottom filter. Thanks everyone！

 

[Trevor033911]

By the way. They all eat a lot everyday and swim strong. Seems like the problem didn't affect their lives.

 

[Andy Sager]

Gill disfigurements are often caused by water quality issues if it's not genetic. For piranha, water quality needs to be excellent, not just pretty good. Ammonia and nitrites are not usually the cause of disfigurements as much as nitrates are. Because Piranha are messy eaters, uneaten food pieces can be in the substrate or decorations rotting causing the nitrate level to be higher. We often see this in overcrowded tanks of fish fry so daily water changes are needed to keep the water clean.
The close up picture shows some areas of the gill plate that may have infection so what I would do is in a separate hospital tank with new, clean water, I'd take the 4 infected fish and and place them in the hospital tank and treat them with Nitrofuracin green if your pH is under 6.8 OR Kanamycin if your pH is above7.2. IF your pH is between 6.8. and 7.2, treat using both the kanamycin AND nitrofuracin. For some reason, there is a special synergy where the 2 meds work together for a more potent treatment but as you can see, that window of opportunity where it works is rather small.

Hope this helps.

 

[V227]

The gills are definitely inflamed.
If you notice the fish flashing or doing head twitching, the problem might be Gill Flukes.

If those symptoms exist. Praziquantel would be a good medication option.

 

[Trevor033911]

鳃畸形通常是由水质问题引起的，如果不是遗传因素。对于食人鱼来说，水质需要非常好，而不仅仅是“还不错”。氨和亚硝酸盐通常不像硝酸盐那样容易导致鳃畸形。由于食人鱼吃东西比较邋遢，未吃完的食物残渣可能会残留在底料或装饰物中，导致硝酸盐含量升高。我们经常在鱼苗过多的鱼缸里看到这种情况，因此需要每天换水以保持水质清洁。
近距离照片显示了鳃板某些区域可能感染，所以我会在一个单独的鱼缸里用干净的新鲜水冲洗，取出4条感染的鱼，放入鱼缸。如果鱼缸的pH值低于6.8，就用呋喃西林绿；如果pH值高于7.2 ，就用卡那霉素。 如果 鱼缸的pH值在6.8到7.2之间，就同时使用卡那霉素和呋喃西林。不知何故，这两种药物之间存在一种特殊的协同作用，可以产生更有效的治疗效果，但正如你所见，这两种药物起效的机会窗口相当小。

希望这有帮助。（是）

Thank you very much Andy! Today I just test the nitrate is around 25-50mg/L. I'll change water frequently. And I just realized this tank might be suffering from a lack of oxygen. I test the oxygen is around 3-4mg/L. So I turn on the oxygen pump. Hope this will help them.
And thanks for the treatment recommendation! Thanks a lot.
By the way do you think this tank is a little bit small for these piranhas? My tank size is 895mm*395mm*570mm around 43 gallon with 6 gallon bottom filter.

 

[Trevor033911]

Thanks a lot V227! I didn't saw fish flashing or doing head twitching. So maybe is not Gill Flukes. I'll treat them with gills inflamed! thanks!

The gills are definitely inflamed.
If you notice the fish flashing or doing head twitching, the problem might be Gill Flukes.

If those symptoms exist. Praziquantel would be a good medication option.

 

[Andy Sager]

Thank you very much Andy! Today I just test the nitrate is around 25-50mg/L. I'll change water frequently. And I just realized this tank might be suffering from a lack of oxygen. I test the oxygen is around 3-4mg/L. So I turn on the oxygen pump. Hope this will help them.
And thanks for the treatment recommendation! Thanks a lot.
By the way do you think this tank is a little bit small for these piranhas? My tank size is 895mm*395mm*570mm around 43 gallon with 6 gallon bottom filter.

Yes, way too small for adults so if they are still small, prepare yourself for a large tank upgrade as they grow. The more water you have, the cleaner the water will be after feeding but that doesn't mean you can slack off on water changes.