Please visit our Sponsors

FAQs on the Alestiine Characid Fishes 

Related Articles: Alestiines, Characoids/Tetras & Relatives,

Related FAQs:

Congo tetra swollen.    3/30/18
Hello crew. Hope you are doing alright.
Today one of my Congo tetras, the biggest and dominant male appeared with a big swollen and open mouth. His head looks very red and swollen. He is still responding to stimulus but very weakly. His condition is worsening by the hour, so this is a very aggressive ailment. He was not like this yesterday. Other notable symptoms are an under jaw with marked veins, a small blood blotch near the pectoral fins.
This looks horrible and I've never seen anything like this. He does fight a lot with a certain other male to the point of pursuing each other across the whole 150 gallon aquarium they are in.
I've had my group of Congos for two years now. When i first got them they came with a type of mouth fungus, something that looked like they are white gums and no teeth (its the closest i can to describe it). It never got bad and it went away once happy in my tank. Now all of a sudden this. I checked the other Congos and there is one with the same white gum thing that i saw two years ago, but it is not hindering in normal feeding or behavior. I conducted a large water change (50%).
I have quarantined the sick fish into a 5 gal bucket with 1/2 Methylene blue and will be waiting on response. Its 8 pm and i don't think i can go get anything difficult right now and i don't think he will make the night if i don't do something right now.
I have malachite green, Metronidazole, and Levamisole in my med box. Any opinions crew?
<This does look like the infamous 'Mouth Fungus' to me, which despite its name, is a bacterial infection nowadays more often called Columnaris after the bacterium species responsible, Flavobacterium columnare. It can be extremely aggressive, and while it can be treatable, you need to work promptly. A strong, reliable antibiotic is necessary -- Kanaplex of example is known to be reasonably effective. Outside the US, access to antibiotics can be limited, but I have found eSHa 2000 to be quite effective as well, especially if the problem is caught early on (it's less effective once the fish is really weak). Neither Methylene Blue, Malachite green, Metronidazole, or Levamisole are useful here. Do bear in mind Columnaris is opportunistic and to some degree caused by things like fighting and less than perfect water quality, so reviewing the tank is important as well. Cheers, Neale.>

Tetra red patch       7/2/14
Dear WWM crew,
Does this (photo attached) looked like a physical injury on my Congo tetra to you? A scrape or something?
<Could well be... that or indication of an advancing infectious situation>

I can see several bright red spots and reddish colour on his belly, as you can see in the picture. The other
side of this fish looks normal: silvery blue.
This is one of a group of 15 or so tetras that I've had for around 2.5 years. There are 10 or so males, fewer females. This one is not the brightest coloured male, but not the palest either.
<A good clue... leading, leaning toward the markings being trauma... from other males>
He looks to be the right shape, no obvious swelling or anything. Do you have any idea what this could be and would you do anything?
<Only guesses as to etiology and no specific treatment... Would just continue to do my best to provide good conditions and nutrition>

The tetras have kind of translucent looking bodies, it always seems to me, so I find it hard to tell whether the red (blood?) is on the surface or somehow beneath some scales.
They are in a planted 220l tank with some wood in it, some of which is a bit twisty and I guess it could be possible for a fish to get stuck in some hole or something and get a scrape). Their tankmates are about 10 small Corys (panda, trilineatus), about 8 Kuhli loaches, 3 Siamese algae eaters (I think they are the "real" ones), a sole surviving guppy that has outlived all my other guppies by miles and some cherry shrimp. The loaches were the most recent addition, over a year ago.
<None of these should be implicated>
I don't notice the tetras being aggressive among themselves and nothing else is big enough to harm them, so I don't think another fish could have injured this one.
<Yes... I had, even spawned Phenacogrammus as a youth... when they mature, they do "joust" about at times very vigorously. I suspect this is what yours are doing... Engaging in reproductive behavior>
One of the other tetras died about a month ago, which is the first time I've noticed one of them dying. I put it down to old age (how long do they live?) or something.
<Mmm, five years nominally under ideal conditions... some a year or two longer>
Actually, now that I think about it I have lost a Siamese algae eater in recent months too. I hope there is not some illness at work in my tank.
<Not necessarily>
I haven't tested the water very recently, but the filter is well established, nitrates tend to sit around 20ppm, and the Corys and shrimp seem to be doing fine, so I'd be surprised if anything was very wrong.
The tap water here is soft: around 2 degrees KH and 3 or 4 GH, so the tank pH sits around 6.8. I guess I'll test the water in the morning (I'm in Australia), especially if you think this could be the result of a water quality issue. I am overdue for a water change - I last changed about 25% of the water about 10 days ago, usually I aim for weekly.
<Good practice; interval, percentage>
Is the picture clear enough to suggest anything to you?
<As above>
I could try to catch that fish out and put him into a smaller tank for a better shot, but that would be traumatic for everyone (catching a particular fast fish out of a school in a planted, wooded tank is not my idea of fun). I'd prefer to leave him be, but wonder if I should be attempting to treat him for something?
<I would not move this fish; as you state; nor treat the system blindly>

I would appreciate any advice you can offer,
<You have it. Cheers, Bob Fenner>

Re: Fwd: Tetra red patch     7/4/14
Thanks very much for your advice Bob,
<Welcome Helen that launched a thou...>
Two days later, the fish looks to be healing from his injury, so I reckon your guess was right. The red marks seem to have faded, though not yet completely. I'm keeping a close eye and am hopeful that he'll recover fully over the next few days.
<Ah good>
Are tetras like these more likely to injure each other if the male/female balance is very uneven?
<Mmm; yes; likely so>
I always had more males than females in this group, and having done some careful head-counting the other night, I reckon that the one that died months ago must have been one of the females, leaving 4 females and 10 males in the school. Do you think that is likely to cause problems and would it help if I tried to get another few females?
<I would trade in half the males... for twice as many females... A dealer/LFS might well do this trade, the males being larger, more beautiful/saleable at this juncture>
They would be smaller, not sure if that would be a problem or not. I'd actually prefer not to increase the bioload in this tank but if it would diffuse aggression it might be a good idea.
Thanks again,
<Welcome. BobF>

Re: Tetra red patch       8/31/14
Hello again WWM crew,
I wrote some time ago about a problem I'm seeing in one of a group of Congo tetras.
<I recall>
The fish in question recovered fully, as far as I could see anyway. But then a couple (maybe a few) weeks later he was injured again. In the same location. That healed up too. Now it's happened again.
<Mmm; this male... is being beaten... the trailing edges of caudal and anal fin are chewed, and blackened... >
I'm assuming it's the same individual each time (though of course they do look alike, so I could be wrong).
Now it seems to me that the chances of the same fish being injured in the same place, in the absence of any other signs of injury on any other fish (i.e. nobody's tail or fins seem to have been ripped, no other red patches or sore looking anything), are pretty slim. So I'm thinking that the original problem has never actually gone away but is partially recovering and recurring. (Either that or other fish are attacking this one in the same spot each time because it looks sore to them too?).
<This is a subdominant fish/specimen... you have a larger, more aggressive male>
I have been considering pulling this one out to a quarantine tank recently, but decided to hold off a couple of days to see if he was healing again.
Partly because I figure it can't be good for a schooling fish to be alone and partly because I quail at the idea of trying to net one particular fish out of this school in my planted tank. But tonight looking at the fish
again his injured side looks worse.
<Needs to live elsewhere>
There is a definite white lump near the middle of the injury. It looks raised. It doesn't look very fluffy/cotton wool like to me, but I can't swear it looks smooth either. Maybe a bit of fluff? It's hard to see.
It certainly wasn't there before, and now I'm more worried.
I'm attaching the best photo we could get, but it's not great. The black arrow points to the white patch I'm worried about. And, as you can see, the rest of the injury looks worse than it did when I last wrote about
this guy. The main area also looks worse to me, actually, as though there may be scales missing or something (again it's really hard to see - these fish are kind of translucent, making them hard to look at clearly, if that makes sense.
You mentioned the idea that the problem might be male-make aggression given that I have 10 males to 3 females in this group.
<Oh yes>
While agreeing with the
idea, I have not been able to source a group of females to add to the tank.
<You may well have to order a bunch (25) and grow them up yourself... sell off the excess males>

Among other reasons, this is because the local aquarium shops are all pretty bad. I buy most of my fish online, but that doesn't allow me to
walk in and choose particular fish.
<Mmm; I'd write to, chat with the fine folks at Drs. F & S re their sorting through, just sending you females: http://www.liveaquaria.com/product/prod_display.cfm?c=747+870+905&pcatid=905
I could get a group of juveniles but they might also be mostly male, so no guarantee that this would solve the problem, if that is indeed the problem. I don't ever actually see these fish acting aggressively to each other, though of course I don't know what they do when the lights are out.
Do you think this could be something other than a physical trauma?
<No; I do not... the primary issue here is mechanical injury... from the other male/s>>
Could the white patch I'm worried about be sign of a parasite (seems unlikely given I've added nothing to the tank in ages), or a secondary infection.
<Poss. this last>
Would you isolate the fish in a breeding net, or a quarantine tank?
<Another system>
(My quarantine tank is 20 litres - I can make sure it is well filtered, but it is too small for the level of activity these fish have).
<Better than naught>
Would you medicate? With what?
<No; none>
I have salt and tetracycline and that's about it (I can get other things, but in Australia we only have access to a very limited set of fish medications).
I'm worried I'm going to lose this guy. And I'm worried that he's suffering now. Any advice you can give me would be welcome.
<Have repeated myself enough I believe>
<Welcome. Bob Fenner>

Re: Tetra red patch     8/31/14
Thanks Bob,
<Welcome Helen>
I have (with many failed attempts and a fair bit of muttering under my breath) caught the injured fish out and put him into my quarantine tank.
I'll see what happens.
<Good... and do learn to use two nets (one in each hand)... much easier>
For what it's worth, I don't think the black on his tail is necessarily injury, as they all have that colouring, and have since I first got them as juveniles. I remember being really worried that they all had fin rot, but looking at lots of images of Congo tetras convinced me that some of them have that patch of black on their tail naturally. Maybe there are different colour variations with and without this?
Drs F&S looks like a great store, but I can't get fish shipped from them to Australia.
<Ohh; yes. Thought you were in the States>
I think I'll wait to see whether this guy recovers or not (and keep a close eye on the others for possible other injuries) and then try my favourite online fish shop (in Australia, of course) to see whether they can sort me out some females.
<It's possible... that w/ growth it might become co-dominant... if there's room...>
Thanks again for your advice.
<Cheers, BobF>
Re: Tetra red patch     8/31/14

<There's another possibility... to breed and raise your own... I WOULD trade in the bulk of your males. B>

Congo tetra with "tinfoil eye"       6/22/14
I have a Congo tetra that has a silvery eye, like there is tinfoil covering it. I got a few Congo tetras yesterday, so it was not caused by anything in our tank. The eyes of these fish are normally large and black.
Does this sound like disease or injury? Thank you
<Without a photo, hard to say. But my gut feeling is this chap has lost his/her eye. Often happens when clumsy or ignorant retailers net them carelessly or pack too many into a bag. The eye gets damaged, and within a day or so, it's gone. Obviously doesn't heal back, but the fish itself is usually not bothered. If the eye is gone, the "solver" will be more or less flush with the head. Sometimes you see deformities to the eye, in which case the silver part covers more of the eye than you'd expect, reducing the pupil to a tiny, sometimes irregularly-shaped spot. There's also the possibility of Pop-eye, typically cased by physical damage, and with appropriate treatment using Epsom salt, can heal with time.
Cheers, Neale.>

Mysterious Congo Tetra Losses, pred.     3/20/13
I have a planted 72 gallon tank stocked with 6 x S. nigriventris (1.5-2"), 4 x M. fasciolatum
<What genus is this? Microctenopoma?>
 (2 x 2" females, 2 x 3" males), 2 x P. pulcher (2.5"),
and 5 x P. interruptus
(2 x 1.5-2", 3 x 2-2.5"). I have had the Congos in the tank for a couple months but over the past two weeks I have lost three of them, two of the smaller size and one of the larger size.
<Mmm... not the Mochokids... my bet is on one of the African Cichlid species, individuals>

They have all died overnight and have had their eyes and fins eaten off when I found them stuck to the intake, but no obvious signs of disease that I could see.
<Mmm; no. Predated>

My water parameters are stable and nothing seems out of place (7.4 pH, 0 ammonia, 0 nitrites, <5 nitrates). Given the irregular nature and timing of the losses, the fact that none of the fish seem in distress when I observe them and all are eating, my guess is predation, which seems to point towards the M. fasciolatum. This doesn't really mesh with what I have read of those fish so is there something else that I am missing or should be looking for? Should I separate the Congos until they are a bit bigger and then reintroduce them to the tank? I would appreciate your help on this issue. Thank you.
Jon Mathews
<Time to do the separation move... Bob Fenner>
Re: Mysterious Congo Tetra Losses    3/20/13

Thank you for the reply. First, yes the genus is Microctenopoma. Second, I am surprised that it would be the Kribensis because they don't seem to care about the Congos when I have watched them during the day.
<It's the nights... but could be your other fishes. At any length, I'd remove the Phenacogrammus>
 They seem far more concerned about the catfish and the Microctenopomas. How big should the Congos be before I reintroduce them?
<Perhaps full size>
The bigger male is already about the size of the Kribs, so wait until the others are as well before moving them back? Thank you.
Jon Mathews
<Likely so. BobF>
Re: Mysterious Congo Tetra Losses     3/24/13

So yesterday morning I looked at the fish and while none of the Congos were dead, I noticed that most of them had wounds of some sort and were huddled in the corner.
 So I transferred them into a 29 gal that I had available (a bit small, but it's temporary). I also noticed that some of the Microctenopoma had white abrasions on their sides as well, so I am assuming
that the Kribensis are the fish at fault here. I have some questions about how to proceed though.
1. A couple of the Congos have big white, raised bumps that appear to have scabbed over and most of the rest appear to have some sort of blood around their fins. Is there any medicine or anything that I need to put in the water to help with the healing, or is this just a waiting period?
<I'd leave off w/ direct med. addn.s... Perhaps add supplements (vitamins, HUFAs) to the foods>
2. Even today, a day after transferring, the Congos are not eating very much. I have seen two of the five pick at the food (flake yesterday, brine shrimp today) but the rest aren't acting interested. I assume that this is a function of the stress and the wounds, but I am wondering if there is anything I can do to encourage them to eat or it's a matter of time and recovery?
<Raise the temperature a bit... 82, 83 F>
3. At this point, I am planning on getting rid of the pair of Kribensis. I made the tank to be a West African biotope and the Kribs were the splash of color for the tank, at least until the Congos got bigger or the Microctenopoma got bluer. Can you recommend another colorful fish from West
Africa that would go with the Congos, Microctenopoma, and USD cats?
<I'd peruse Fishbase.org with the countries involved... w/ the selector for http://www.fishbase.org/search.php
 Information by Country/Island
Aquarium Trade>
These tankmates are most often associated with butterfly fish, but I am not interested in getting one for a variety of reasons. Would any of the Krib cousins (P. taeniatus maybe?) be more nicer to their tankmates (or would not getting a M/F pair make a difference)?
<Not likely much difference here; but I'd look for tank bred/reared vs. wild-collected specimens>
Also, is there an African algae-eater?
<Mmm, yes>
I have not been able to find one, as the normal fish are SA or SE Asia.
Thank you very much for your help.
Jon Mathews
<Enjoy the search... there are other tools... that come to mind, but I'd use Fishbase first. Bob Fenner>

Something not right with Congos and Silvertips  6/19/12
I'm afraid I'm still learning the hard way… Cannot believe I did this…and yet I did.  No quarantine tank and now there's a problem.
Went ahead and added two more Congos and a dozen Silvertips to the mix.  All adapted well, peaceful and active for almost a week now.  The Congo's seem more settled with just a few more in their group - not darting around nearly as much as they were.
Also got a few more clumps of Corkscrew Val - my LFS person suggested that the plants might fare better in a lower temp than 80, so I lowered by 1 degree/day to 78.  I thought this temp change would not affect the fish negatively.  Maybe it did.
<Unlikely; 77 F/25 C is optimal for both these species.>
Four days ago, I noticed what looks like a white pimple on the center of lower "lip" of one of the female Congos, which was one of the original group of Congos.  This is definitely not Ich and not Lernaea - I've had experience with both and this is different. 
<This is something you see quite often when fish are newly introduced. I think it's physical damage more than anything else. Bumping into the glass or hood of the tank perhaps. Treat for Finrot, but otherwise observe and don't panic.>
The rest of the fish is clear and perfect.  No problem eating and is as active as the rest of the group.  No flashing or any other symptom.  At first, I thought it was possibly from banging into something in the tank, but it is perfectly round, and instead of fading like a bruise or injury, the spot became more raised, more pronounced and well-defined, though not larger - more like a whitehead pimple coming to a head.  Two days ago, I noticed the "pimple" seemed to erupt and a few white, filmy trails followed, then disappeared (uh-oh), then the wound seemed to heal.  I thought we were out of the woods.
This morning, I noticed a new spot on the same fish, on one side of its upper lip (white dot on mouth in picture attached), similar to the original pimple, when it first appeared - this one seems less uniform. more ragged.  I also noticed the exact same (new stage) of the pimple on two of the Silvertips - on both, at the center of the lower "lip", so now I think it's definitely more than a bruise or injury, since the Silvertips are not bumping into anything in the tank.  The rest of the Congos are perfect, as are the Emperors. 
Note:  I've actually cut back from feeding twice daily to once daily.   However, I've also caught my 8-yr old feeding the fish outside of feeding times a few times, so there might be uneaten food lying around that I haven't been aware of.  I've done a little educating about overfeeding and I don't think it will be a problem anymore.
As far as the white pimples, I'm concerned about treating for a possible parasite, fungus, or bacteria.  Do you know what this is, or might be?  How would you treat it? 
<See above.>
If treating with meds, would raising the temp help or hurt in this case?
<I would not do anything to move the temperature beyond 25 C/77 F.>
I've attached a few pictures - my camera's not great, so they're not really clear.  I think you can get a good idea though.  The affected Silvertip is the one at the bottom of the picture.
I am concerned about treating a 45 gallon planted tank.  I have a 10 gallon tank that I can set up as a hospital tank, but there would still be the problem of the 45 gallon tank being infected, and all the remaining fish being susceptible to whatever this is.
One more thing - This morning when the timer lights go on (7AM) and the time I usually feed them, all 4 male Congos' fins and the tops of their heads looked bloody.  I've never seen this before and I was alarmed at first, when it looked like they might be injured or sick.  But it was just the males and all 4 had the exact same odd coloration - just the dorsal fins, the anal fins and the tops of their heads.  I checked the water quality and it was fine, except the pH was 8.  It's usually around 7.8.  That's the only change from the normal parameters.  I can't think this was normal or some kind of mating coloration, but it was uniform with all four and then disappeared within 15 minutes or so.  But it definitely seemed bloody and not like a normal coloration.  After they ate, their coloration went back to normal.  Coincidence?
<Congo Tetras can, do change their colours with mood, so if they are otherwise normal -- don't worry! This is a stunning species with colours difficult to describe, and very changeable and oh, so dependent on ambient lighting conditions and mood.>
Have been reading up on the Congos and much of the available info says they do best in softer lighting.  How do I provide enough light for a planted tank and also provide the Congos less intense lighting?
<Allow leaves to grow across the surface. Add floating plants if you can.>
Thanks again for all your help.
Peacefully fishkeeping,
<Cheers, Neale.>

Thank you!  Re: Something not right with Congos and Silvertips  6/19/12
Phew! I can stop feeling like a nervous new mother now. 
BTW - How's that beautiful niece of yours?  Are you a new uncle again as yet?
<She's just fine; thanks for asking. Nope, not been made an "uncle" again, yet.>
Thank you so, so much.
<Welcome, Neale.>

Stocking community tank with Congo Tetras   6/11/12
Hi guys,
It's been a while since I've had to call on you.  And here you are reliable as always.  I have many questions…
<I can see…>
I recently set up a 45 gallon tank.  Started new - Eheim for 65 gallons, Eco-complete substrate, aged bogwood and a few immature clumps of Jungle Val., Corkscrew Val, Cryptocoryne, Wendtii and a little Anubias on the driftwood.  Nice enough, but still quite sparse.  The tank cycled for about a month.  Ammonia, nitrate and nitrate are "0".  pH is around 7.8.  Temp maintained at 79-80 degrees.  25% weekly water changes for the past two weeks.  Dosing weekly with Seachem Excel and Iron for the plants.  Lights on timer for 12 hrs/day.  Do you have a preference fro Seachem Stability or Hagen Cycle?
<Both are as good as each other -- which isn't saying much. None of the products marketed as "jump starting" biological filters work especially well or reliably. I wouldn't trust them. Use them by all means, but if you want to save your money, do so, and you won't see much difference. The plants would have brought in starter cultures of bacteria, and if you're adding ammonia and been running the tank for a month, the filter should be well established. There's absolutely no need to "top up" biological filters with new bacteria each time you do a water change, whatever the manufacturers of these filter supplements might suggest.>
I thought I was going to make it a South American biotope with Emperor Tetras, Angels, etc., until I went shopping a week ago.  My reliable LFS is going strictly saltwater and is having a fire sale on all freshwater livestock.  He had three beautiful Emperors - I got them a week ago.  1 male and 2 females.  My 8 yr-old daughter fell in love with the Congo Tetras.  We got 5 - I think we have 1 male for sure, maybe 2 (some are young).  I wanted to see how they got along with the Emperors before adding more.  They are fine together.
<They should be fine; while the Congo Tetras are much bigger, they're not an aggressive species and prefer open water. Emperor Tetras mostly hang around the plants.>
Since the Congos are very skittish, would more plants help?
<Possibly, but it's more about the size of the group -- they're very social.>
It's in quite a high traffic area - around the corner from the kitchen.  Would they do better in a larger group?
I'd like to add a few more to total 7 or 9, but I wonder if the tank is too small (not long enough for them to cruise).  Any thoughts?  Or would it be best to exchange the fish for something else?
<Your tank is a bit small for Congo Tetras, yes. How long is the tank? I'd recommend at minimum 120 cm/4 ft. Depth is less critical.>
I'd like to add 6 Ember Tetras - that's all LFS has left.  Would the Congos see them as a snack?
<Quite possibly.>
I realize my water may be more alkaline than recommended for these, but it's the same pH as in the LFS and in our general area and they seemed fine in the shop, so far.
<Often tetras seem to adapt to hard water, but their longevity is noticeably less.>
It would be nice to have some good movement at the upper levels of the tank.  Would a shoal of Silvertip Tetras be a good addition here - 12+ or so?  What's the maximum number you would advise?
<A school of 10-12 would be a good choice for a tank like this.>
Would either or both of these tend to harass the Congos?
<Silvertips are usually peaceful if kept in a large group. They're not nearly as persistent fin-nippers as, say, Serpae Tetras.>
So depending on what you advise, I might add a few more Congos, and some Embers and/or Silvertips, OR get rid of the Congos (really don't want to do this) and add the Embers and Silvertips.
<Congo Tetras, Silvertips and Emperor Tetras should all get along. Ember Tetras are very much "nano" fish to keep with similarly small tankmates.>
I'll add some Java Moss to the mix next week.  I've always had good luck growing moss on wood, but I've recently seen some as groundcover and can't figure it out.  Can you tell me how this is done?
<Tie some to a weighty object like a bit of driftwood, and as it grows, it spreads and sticks to the gravel. Once done, cut away the weight, and off you go!>
Would it be a good idea to add a few Otos or Cherry Shrimp or not?  Am I overstocking at this point?
<Shrimps work well with small tetras like Ember Tetras, but I wouldn't keep them with much bigger species. As for Otocinclus, I'm not a huge fan because they need quite cool, oxygen-rich water to thrive, but what the heck…>
Another question, if I may…  The lighting is quite bright.  Would the fish be happier with more subdued lighting?
<Yes; or at least, a mix of shady and open areas.>
I may try to find some Hydrocotyle so when it matures, it would minimize the lights somewhat.
You've never steered me wrong.
<Cheers, Neale.>

Congo tetras with Finrot  2/17/12
Dear WWM crew,
Firstly, thanks in advance for your advice!  I don't normally need to read the WWM pages about medications and diseases, but sadly today I find myself doing so :(
<I see>
I have just received a batch of 10 Congo tetras in the post
(lacking a car it's usually easier for me to order fish online than to drag myself, toddler and baby to an aquarium shop).  They look ok, not that I'm expert in the species. 
While they are not coloured up yet, I can see hints of the shiny reflective colouring that I'm hoping to have resplendent in the future.  But some of them (maybe all of them?) have what looks to me like Finrot.
<Phenacogrammus do ship rough... often appearing like you describe on arrival. Given suitable circumstances, feeding, they rapidly "bounce back" into good shape>
I have very little experience at treating aquarium diseases.  Usually I manage to keep sick fish out of my systems in the first place.  But I suspect that these guys need treating.  Several of them have a white line at the edge of their tail or fin that I think is the Finrot in action, some of the fins look eaten away and on one of the tails I can clearly see that the web is eaten away leaving just the rays.
<I suspect this "rot" is simply "ammonia burn"; again, from shipping conditions>
They have been in the post for two days coming to me
<Quite a long time... about the limit for most aquatic livestock>
 and when they arrived the ammonia level in the bags was off the scale (at least 8ppm on my API drop test, if one can rely on any accuracy at that level).  The pH was only 6 (or maybe lower - again that's at the edge of the test and I wouldn't trust it to be accurate, though I assume the PH was definitely low.  I don't know whether that level of ammonia would have been harming them or not, given the low pH.
<Not as much, thank goodness... Had the pH been high, they'd all be dead>
I have slowly acclimatised them to a quarantine tank with pH 6.8, ammonia 0, nitrite 0, nitrate 0, temperature 25.5 degrees.  There's no nitrate because I have just set it up, but I've put mature filter media from my main tank into the filter, so hopefully there will be no trace ammonia or nitrite showing up. 
If there is, I'll use Seachem Prime to reduce the impact and add more filter media or Zeolite or similar to help.
I'm planning to feed these guys a mixture of baby brine shrimp and flake and small sinking pellets.  I'm planning to keep them in quarantine for at least two weeks or until they seem well.
So my questions are:
1.  Would you treat the Finrot or let it alone and see what good water conditions and good food can do?  My inclination is to think it needs treating, but I'm not sure.
<I would either not treat, or use something "very gentle"...>

2.  If you suggest treating the Finrot, what medication would you suggest that I can get hold of here in Australia, where medication options are fairly limited?
I can get tetracycline, Myxazin, triple sulfur,
<This... the Triple Sulfa, if anything. 250 mg.s per ten gallons, water change every three days for three treatments>
promethaysul, Methylene blue, and that's about it for things that claim to treat something like Finrot. 
Would any of those be likely to help?  Or might they just harm the already stressed fish further?
Do you have any other suggestions for me?
<To enjoy your new charges>
Thanks again,
<Welcome. Bob Fenner>
Re: Congo tetras with Finrot, ammonia burn f' as well  – 12/17/12
Dear Bob and Crew,
Thanks very much for your advice.
This morning when checking the fish I notice that several of them have blackish marks on their tails or fins.  I didn't notice that yesterday afternoon but the light was different so maybe it was there and not so obvious as now.
However, I am inclined to guess that these are the marks of now-healing ammonia burns (something I've not seen before but have read about).
<You are correct>
  I've attached a photo, not a great one but the best I could manage.  You can see the black marking on the fish's tail.  Do you agree this is likely to be ammonia burn?
If so, would you recommend any treatment other than good water, good food, and time?
<Not really, no>
  How long would you expect the fish to take to heal?
<A week or two>
  I certainly wouldn't want to put them into my main tank when they are still injured.
Thanks again,
<Certainly welcome. BobF>
Re: Congo tetras with Finrot    2/26/12

Dear WWM Crew,
<Greetings again Helen>
Thanks again for your advice.  I just wanted to let you know that 9 of the 10 fish are healing nicely from their Finrot.  Actually only one of them, the worst injured, has real signs of it any more.
The 10th got sick with what I think was some other problem, losing its "balance" in the water more and more increasingly.  When it got to the point where it was struggling to stay floating and I had no idea what was wrong or how to treat it,
I euthanised it with clove oil rather than risk it dying and being eaten by the others overnight and then the rest of them catching whatever it had. 
These things happen, and so far (a week on) the others seem fine.
Thanks again!
<Thank you for this follow-up. BobF>

Green Terror Cichlid W/ Congo Tetras and a Convict  716/10
Hi Crew, I have 55 gallon, 100 cm long tank and would like to keep one male display Green Terror with a school of Congo tetras. The Green Terror will be introduced as a juvenile. Would this combination be fine?
< When the green terror gets bigger and figures out how to catch the Congo tetras they will probably be in trouble.
Also, what other suggestions are there as to what else I could keep with them in a tank of this size?
< By using the term them I think you are talking about the Congo tetras.
They usually hang around the mid water column, so anything that stays close to the bottom and is about the same size should be fine.>
Would an additional male convict cichlid be asking for trouble?
< A single male convict would be OK with a school of Congo tetras. They should be fast enough not to be caught by the convict.-Chuck>
Thanks Tim

Re: Your opinion? Congo Tetras...    2/9/10
Good afternoon Neale, you wise British savant knowledgeable in the way of fish.
I have yet another question. My Congo tetras are nipping my butterfly fish (and sometimes stealing their food).
<Unusual. Congo tetras are not normally nippy. Indeed, they're usually the ones that get nipped!>
The plant is very well planted on the bottom and half the top is totally covered in floating plants as well. The floating plants have roots that hang at least 4 inch's in many cases. Its total jungle in there.
<Sounds great!>
My eight Congos normally only bug each other in their endless war of dominance, however when its feeding time they drive the butterfly's crazy nipping on the dorsal fins. Is separation the only option?
<Does sound it.>
Oh and the dominate Congo's rear fin is developing a black triangular extension, its small but noticeable. Is this normal?
<Yes; the tail fin of Congo tetras develop a black band running from the peduncle the edge of the fin, like a horizontal stripe. Cheers, Neale.>
Re: Your opinion? Now onto Exodon...    2/9/10
Thanks man. The tank is coming along great with your help.
<Glad to help.>
PS: watching Congos eat a full grown insect is a surprisingly educational experience. They are a hunting pack like any other eh.
<Oh yes, indeed! Piranhas are simply scaled up tetras. Do look out for Exodon paradoxus. Very beautiful fish, and if kept in large groups, quite peaceful towards one another. But throw in a piece of tilapia fillet and they go bananas, a true feeding frenzy. Because they're so small, and both pretty and active, they are far better pets than Piranhas, in my opinion, which tend to be rather boring. They also do well on flake, so aren't difficult to maintain.
Cheers, Neale.>

Congo Tetra with red spot on his head. -- 4/17/09
Howdy, y'all rock!
<Modest forbids...>
I have a problem, well I have a bunch of them but that is a different story :)
My Congo Tetra has a red spot on his head, right at the top of the gill.
Pictures are worth a thousand words so check out the attached pictures. You can find the full size images at.
You really need to look at the full size images, the images I attached don't have all the detail you need. I figured you didn't want me sending multi-megabyte pictures.
Oh boy, this history on this fish is too long. He has survived cotton mouth and various other ailments in his 4 year life. Some of our other fish were not so lucky with the cotton mouth. We found some red spots on our Congo Tetras shortly after the cotton mouth cleared up. It killed our other Congo Tetra. It spent over 2 weeks in a 10g quarantine tank before it got better.
We tried Maracyn, parasite killer and some food laced with antibiotics (I can't remember the names of the treatments). That was about 3 months ago.
Since then the tank has been stable and no problems.
Yesterday we found the spot. Any ideas?
<Very difficult to say; most likely physical damage and/or secondary infection. An antibacterial treatment should help, but double check water quality and relationships with other fish. Congo Tetras are quite nervous animals, and apart from being nipped, they can jump into the glass or hood when alarmed. Anyway, assuming the water quality is good (0 ammonia/nitrite) and water chemistry within the range for the species (pH 6-7.5, 5-15 degrees dH) I'd treat as you would Finrot, and hope for the best.>
I am hesitant to move him to the quarantine tank, he just darts around and beats himself up on the glass and we don't want to get a bigger QT tank right now.
<Don't quarantine a single Tetra; as you say, he's not going to like it.>
He is exhibiting no odd behaviors, his eating and activity are normal. The other fish don't have any signs of damage. We have just used some Melafix in the tank, our Yellow Spiny Eel dug himself into a hole and lost some skin, used the Melafix as preventative measure.
<Melafix pretty unreliable.>
The eel was 100% better after only a few days.
<Unfortunately these small Spiny Eels (Macrognathus spp.) do get damaged by gravel, and in my opinion, should only be kept in tanks with a soft, sand substrate.>
What the heck do we have, and don't tell me a tank full of fish:) And what do we do about it.
<Some type of antibiotic or antibacterial; Maracyn is as good as any place to start, but anything that combats Finrot should work.>
Levels are good. Nitrate 0, Nitrite 0, Ammonia 0, Phosphate trace.
CO2 is controlled at 7
Temp is a 79 degrees
Lots of plants
Lots of fish.
2 Eheim 2213 filters
1 UV Sterilizer.
Lots of lights.
2 cubes of blood worms every night. There are no leftovers.
Thanks for any, and all help.
<Hope this helps, Neale.>

Aggression in Congo Tetras 7/9/07 Greetings, Crew! I wish this site had been available to me 35 years ago, when I first started keeping fish...this is hands-down, the most helpful source of aquatic information that I have found. Thanks for all your caring and hard work! I've been a long-time "lurker", but this is my first time asking a question. I had a group of six Congo Tetras that I purchased locally about four years ago. They were juveniles when I bought them; it turned out that I had two females and four males. <Greetings! Congo tetras are among my favourites.> Everything seemed fine until recently, when I lost the females and one of the males over the span of about a month. There would be a "sudden death"...no warning, no strange behavior, water parameters were stable, and right on. (125 gal tank, Eheim 2028 canister filter plus a Tetra 60 hang-on, plus the weekly use of a Vortex diatom; ph 6.8, temp. 78, ammonia and nitrates 0, nitrate 5.0 or under. <Interesting. Conditions sound perfect.> Mixed fake and real plants, driftwood, sand, gravel and pea-gravel substrate. Tank inhabitants: 6 giant Danios, 7 red serpae tetras, 6 Glowlight tetras, 7 red-tailed rasboras, 1- 4" Pleco, 3- 3" clown loaches, 1- 6" striped Raphael cat (he's been with me for at least 6 years), 2- 8" banded Leporinus and most recently, 3 koi angel fish that were about the size of a quarter, but are about double that now. <Some "courageous" choices as we say in England. Angels and Serpae tetras are usually a VERY bad combo, because Serpae tetras nip slow fish with long fins, and Angels are slow fish with long fins. Leporinus fasciatus are famous for being aggressive and having huge teeth that can shred pretty well anything. I have known experienced aquarists who describe them simply as "evil"!> Quarantine tank used religiously, water changes of about 20% twice a week. Foods are various Tetra brand flake and granular, Spectrum pellets, peas and frozen blood worms) <All sounds very good.> After the first Congo turned up dead, I started to watch the tank dynamics more closely. There has always been a good bit of excitement around feeding time, but the Congos were actually beating each other to death! About a half-hour after feeding, the Congos would start displaying and slamming into each other, sometimes so violently that there would be scales knocked free. None of the other species of fish took part, or were targeted by the Congos. <Well, the obvious thing to do would be remove some of the males and add more females. A school of 6-8 specimens should work, and certainly did for me.> I'm now down to the remaining three males, and it seems that they have come to a truce...I've seen no more violent behavior. I would like to add a few more of these beautiful fish, but I'm hesitant to do so, fearing that the new ones may suffer the same fate, or that the new introductions may spur a whole new round of violence. <The best solution might be to re-home the 3 you have, at least temporarily, add 6 more Congo tetras, and once they're settled in and sufficiently large, add the other 3 back.> Can you offer any insight? I've done some researching of these fish, and don't find any mention of this belligerent behavior. Thank you. Tracy G. <The social dynamics of schooling fish can be very variable, and I've seen similar things to this in a variety of supposedly schooling fish, from Danios to archerfish. Generally, the bigger the group, the less problematic, so adding more will be your best chance of fixing things. To some degree, all schooling fish use bullying to establish a hierarchy. I'm watching the Asian glassfish in my aquarium here right now, and these fish are constantly dive-bombing one another. While this adds to the fun-value of schooling fish, if the numbers are too small this jostling of position can lead to damage or death, as you've discovered. Adding 6 more Congo tetras should be fine, as the three left will not be able to harass these too much. Since you have a big tank, adding more fish shouldn't overwhelm the filter. Good luck! Neale>

TigerFish (HYDROCYNUS VITTATUS) Dear Bob I would like to enquire about a market for live tiger fish. Is there a market for live tiger fish? <Yes, but a limited one... do to their size, voraciousness, and difficulty in shipping (they don't move well)> Who would be the best candidates to purchase live tiger fish? Could you let me know if it is possible to export live tiger fish to the USA? <If I were a supplier, I'd try various freshwater wholesalers... or if you just wanted to sell to one, contact Steve Lundblad at Dolphin International (Los Angeles) re> Would it be possible to give me a couple of names of live fish distributors in the east (Japan, Taiwan, Thailand, China)? <Please see the O.F.I.s listing here> I heard from someone that there was a big market for these live tiger fish in the east, but after searching far and wide, I have not been able to get any detail ... Please can you help? Freddie <I don't think this market is large... I would look into selling at least other African species as well... Bob Fenner>  

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: