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
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
<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
to you? A scrape or something?
<Could well be... that or indication of an advancing infectious
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
<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
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.
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?
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
<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
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.
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
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
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
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
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:
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
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
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
<Poss. this last>
Would you isolate the fish in a breeding net, or a quarantine tank?
(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?
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
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
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
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
<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
<It's possible... that w/ growth it might become co-dominant... if there's
Thanks again for your advice.
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"
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
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.
Mysterious Congo Tetra Losses, pred.
I have a planted 72 gallon tank stocked with 6 x
(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
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.
<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.
<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
Africa that would go with the Congos, Microctenopoma, and USD cats?
<I'd peruse Fishbase.org with the countries involved... w/ the selector
Information by Country/Island
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.
Also, is there an African algae-eater?
I have not been able to find one, as the normal fish are SA or SE Asia.
Thank you very much for your help.
<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
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?
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
<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
Thanks again for all your help.
| Thank you! Re: Something not
right with Congos and Silvertips
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
<She's just fine; thanks for asking. Nope, not been made an "uncle" again,
Thank you so, so much.
Stocking community tank with Congo Tetras 6/11/12
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
<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
<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
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?
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
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
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
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.
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 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
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
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
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
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
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
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>
<Welcome. Bob Fenner>
Re: Congo tetras with Finrot, ammonia burn f' as
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
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.
<Certainly welcome. BobF>
Re: Congo tetras with Finrot
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
<Thank you for this follow-up.
Green Terror Cichlid W/ Congo Tetras and a Convict
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
< 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
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
Re: Your opinion? Congo Tetras...
Good afternoon Neale, you wise British savant knowledgeable in the way
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
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,
Re: Your opinion? Now onto Exodon...
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.
Congo Tetra with red spot on his head. --
Howdy, y'all rock!
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
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
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
<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
Levels are good. Nitrate 0, Nitrite 0, Ammonia 0, Phosphate
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>