Bloated/lumpy cardinal tetras

Hi all,

A few of my cardinal tetras look like they've severely over eaten, and a couple of these also misshapen under their bodies. There's also some white on some of their fins and one has discoloured head/gills. No raised scales or pineconing, haven't caught anyone doing any weird poos, can't see any fuzz, worms or other lumps raised or protruding on their bodies.

Please see attached pics - these are two different fish.

We haven't had a fish death in over a month and haven't added anything new since a few weeks before that, but when we last did it was 2 cardinals on consecutive days. I worried they'd over eaten and reduced feeding and haven't had any more issues, but these fish still look wrong/haven't recovered so I'm worried.

Ammonia and nitrite 0, nitrate can get up to 60 before a water change but hasn't gone above and is usually 20-40. Water temp 25C, volume 150L.

Any idea what it could be and how I treat it? Or should I just wait and observe for changes?

None of my LFS seem to stock much seachem stuff but I could order online, it's just expensive so I want to make sure I'm getting the correct thing. I've had bad experiences with Melafix and Pimafix so I don't want to go there again.

Tank inhabitants: 3 honey gouramis, 6 corydoras, 2 otos, 4 guppies, 7 cardinal tetras.

Thanks for your help and advice!

 

The fish in the first picture is badly diseased. It’s tissues look necrotic and I see the beginnings of pineconeing. It’s beyond help and no amount of medications dumped in the tank will make a difference. The other fish appears to be well-fed female.

 

Hi rissa007
Welcome to the forum .
The fish in the first picture may well be beyond help. It might even be best to cull it now or at least watch it every couple of hours and be ready to remove the carcass as soon as possible.

In the interest of limiting future bacteria issues I can recommend rooibus tea and Indian almond leaf. While this may not be an instant fix it might help in the future to have these tannins in the tank?

It may take time for the humans to adjust to leaf litter and tannins in the water but the fish will appreciate it straight away.

 

Thank you both! So best to remove that first poor guy to limit spread to others?

I have some IAL on hand so I'll pop some of those in. I haven't really used them before - how many would you add to a 150L tank, and would you introduce gradually or just chuck the whole lot in at once?

 

I have always added only a few at once , but reading what other people say they do on this site I may have been to cautious?

To answer your question is difficult because IAL grows in different sizes , it’s picked at different times of the year and has dried out depending on storage.

As a guide in a 150 litre you could add 6 large leaves no problem. As this is for medical reasons not just looks you could easily increase that number.

At least in the short term I encourage you to persevere with the look of natural brown water.

 

Thank you both! So best to remove that first poor guy to limit spread to others?

It's an opportunistic bacterial infection. It's similar to Columnaris in its symptoms and expressions. These bacteria are omnipresent and only affect weakened fish.
Not only remove the fish, euthanize. It's suffering.
Against it there is only one way: Prevention via optimisation!

I have some IAL on hand so I'll pop some of those in. I haven't really used them before - how many would you add to a 150L tank, and would you introduce gradually or just chuck the whole lot in at once?

Well yes, add at least 5 medium sized Catappa-leaves and keep adding regularly. They should stay in until completely decomposed to botanical mulm. Helps the balance of the tank. I add a handful of leaves every two weeks.
Also think about removing the livebearers and softening the water by dilution with rainwater or RO.

Ammonia and nitrite 0, nitrate can get up to 60 before a water change but hasn't gone above and is usually 20-40. Water temp 25C, volume 150L.

Cardinal tetras are decidedly softwater fish, they react very badly to high nitrates and especially ammonia. They don't cause the disease, but they cause the stress that lowers their immune response. But this is only half of it, because the nitrogen compounds are water quality, not parameters. And for Cardinals, which are still mostly wild caught, over 25mg/l of nitrate means bad water quality and thus a permanent stress factor. If you can, get more floating hornwort and other quick growing plants. That will be helpful.

What are the actual water parameters: GH, KH, pH?

The fish in the second picture is definitely just fed well. Think about feeding the cardinals at a separate spot, as they don't have sense of when to stop eating. That's why they tend to fatten up quickly and eat until they drop dead.

None of my LFS seem to stock much seachem stuff but I could order online, it's just expensive so I want to make sure I'm getting the correct thing. I've had bad experiences with Melafix and Pimafix so I don't want to go there again.

General advice: There are only a handful of diseases and parasites that can be targeted with meds well, safe and secure. Most meds on the market do not cure what they are said to because overuse has made many pathogens resistant.

I have always added only a few at once , but reading what other people say they do on this site I may have been to cautious?

To answer your question is difficult because IAL grows in different sizes , it’s picked at different times of the year and has dried out depending on storage.

As a guide in a 150 litre you could add 6 large leaves no problem. As this is for medical reasons not just looks you could easily increase that number.

At least in the short term I encourage you to persevere with the look of natural brown water.

The main problem is that the process of microorganisms colonizing the leaves takes up oxygen. So the amounts that can be added at once are limited, the overall amount that can stay in a tank is much, much higher.

Here an example of prime Cardinal tetra habitat in a tank. Right now I don't keep the species since the last one died of old age last year.

 

In Australia IAL can be expensive most of the time. Well in my town they are. For a couple of dollars I buy rooibus tea bags.
I use a bucket to have strong tannins ready to add to all water changes.

 

I don't use catappa regularly either. Rooibos I use mostly for the colour, otherwise alder cones and mixed autmn leaves collected in the woods:

Beech, Chestnut, Oak and Walnut

 

Just to add that for me this is a problem with Columnaris, probably both fish as all fish in the tank will have the organism living on their skin. Usually the immune system prevents the bacterium from causing damage to tissues and it feeds on dead skin etc.

The bloating could be a failure of the sick fish to osmoregulate. It will swell up with water in the body cavities if it isn't effectively pumping it out via the gills and kidneys. Columnaris on the gills isn't that easy to see but is very common site of infection.

My experience of this disease on Neon Tetras led me to optimise the living conditions of the fish. After initial severe losses many of the white skin symptoms gradually disappeared and some fish appeared to return to full health although a fish a month was lost for a while. Also some fish succumbed to gill infection seen as rapid breathing. This also occurred in old age of this group.

Regarding medications I have only heard of the antibiotic Oxytetracycline being effective in aquaculture. There seems to be no description of successful treatment in aquaria available.