Congo Tetra strange marks

Hi guys,

I recently got some XL Congo tetras from my lfs and noticed straight away that two of the males have these strange markings on their side. It looks almost like an old injury, that has healed over leaving some discolouration. The store said they had been quarantined for 3 weeks and seemed fine, although one of the males also has a crooked jaw, but is eating fine.

I have been treating the tank with melafix but am wandering if this mark is anything to worry about, or is like I thought, simply an old injury.

Thanks

Never treat a tank without knowing what you are treating it for.

I am treating my cardinals for fin rot. Is is harmless to other fish

Just thought I’d was relevant to mention…

Oli said:

I am treating my cardinals for fin rot. Is is harmless to other fish

Just thought I’d was relevant to mention…

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Melefix really isn't the greatest thing to use for treating fin rot. It contains Aloe Vera which can be harmful to your fish.
I would never add it to my aquarium.

For fin rot, I would simply use salt and clean water.

This forum was asking about the mark on my congo tetra. Please only comment relevant information to the question.

Oli said:

This forum was asking about the mark on my congo tetra. Please only comment relevant information to the question.

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If you don't want knowledge, your choice. Knowledge is power. I was only trying to help you care better for your fish.

No medication is harmless to fish. None. Any substance that dissolves in the tank water has the ability to enter the fish if it can diffuse across the cell membranes. The substance enters the bloodstream and is carried to the internal organs. This can cause stress, or far worse, depending upon the substance. Fish "drink" by taking in water via osmosis through their cells. The kidneys work to filter out toxins into the urine. But damage from the toxin (all medications, minerals, chemical additives) often results.

Diagnosing fish issues is certainly very complex. The hobby manufacturers provide us with an array of "medications" that are frequently no better than "magic snake oil."

I consider this to be extremely relevant to the discussion. Many aquarists, certainly myself some years ago, have killed more fish trying to "cure" them that actually would have died from the "disease" or problem. We become better aquarists by learning as we go, from our mistakes as well as from more knowledgeable aquarists.

Okay so should I be worried about the above Congo tetras? My lfs have said they came from a very long term customer and it appears to be scarring from an old injury, but they are happy to refund?

Oli said:

Okay so should I be worried about the above Congo tetras? My lfs have said they came from a very long term customer and it appears to be scarring from an old injury, but they are happy to refund?

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I never guess when it comes to offering advice on issues like this. If this really is a "scar" from an injury, then the fish will either be fine or it will die, but it will pose no threat to other fish which would be the worry if this is something else like bacterial. If the store is willing to give you two more, all well and good. If these two are actually fine, that makes a larger group and the Congos will without question be less stressed and more enjoyable to watch. Though I do not know how many you have, but 10-12 is what I would consider absolute minimum, and a few more if space permits, all the better.

First off, there is no aloe vera in Melafix. There isn't much in Melafix, but I just checked their info sheets and didn't find that.

I am afraid to diagnose as I think it could be the disease no one wants to admit. It looks like a Mycobacteriosis lesion on the flank of that fish, and combined with a crooked jaw, that incurable disease is a possibility. Fish can live years with it, but with a sudden stress (like moving) it can blossom. To be sure you need a lab culture that costs a fortune and takes weeks.

I would not take the risk, and would return the fish. Actually, I'd euthanize them if I became more certain, but from a photo, it isn't easy.

GaryE said:

First off, there is no aloe vera in Melafix. There isn't much in Melafix, but I just checked their info sheets and didn't find that.

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My bad. The aloe vera is in Melafix Marine

GaryE said:

First off, there is no aloe vera in Melafix. There isn't much in Melafix, but I just checked their info sheets and didn't find that.

I am afraid to diagnose as I think it could be the disease no one wants to admit. It looks like a Mycobacteriosis lesion on the flank of that fish, and combined with a crooked jaw, that incurable disease is a possibility. Fish can live years with it, but with a sudden stress (like moving) it can blossom. To be sure you need a lab culture that costs a fortune and takes weeks.

I would not take the risk, and would return the fish. Actually, I'd euthanize them if I became more certain, but from a photo, it isn't easy.

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Hmmm that is worrying. I’ve noticed they are not behaving as previous congos have. They have been bunched up in the corner pretty inactive, and the more I look at them, the more I see they look worse for wear. The shop has agreed to offer a full refund so I will return them on Sunday. Such a shame as they truly are some of the biggest congos I’ve seen, but they were also expensive. I think I will instead replace them with some of the younger, healthier looking congos they often have in, and up the numbers as recommended

Oli said:

Hmmm that is worrying. I’ve noticed they are not behaving as previous congos have. They have been bunched up in the corner pretty inactive, and the more I look at them, the more I see they look worse for wear. The shop has agreed to offer a full refund so I will return them on Sunday. Such a shame as they truly are some of the biggest congos I’ve seen, but they were also expensive. I think I will instead replace them with some of the younger, healthier looking congos they often have in, and up the numbers as recommended

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And try for a mix of male/female, around half/half is good with this species. When I had 12 they were half/half and it worked well; the females were not very noticeable, true, but they were there serving their purpose and the males were all the more active as a result.

So I returned the congos and finally got my dream fish! A pair of discus. I know these are recommended in groups but the store said these 2 had started showing aggression to the rest of the group and showed signs of pairing off! (I hope so as cost a fair bit ) Here’s to hoping to some eggs in the next couple weeks so happy!
(The denison barbs are being collected later today so as not to stress the discus)