Catfish: has a red bump?

  • #1
Hey Guys,

I would really appreciate it if someone could help me out... my catfish one large one and one small one, both have a redish bump just above their gill and under their right eye... if anyone knows what it is or better yet what I could do to fix it, I would be so so grateful.
anyways I've attached a photo of the large catfish and his spot, hope you can see it.
  • #2
This might be able to help you diagnose your fish somewhat. I am at a loss and will direct Dino to this thread. Welcome to FishLore, and hopefully we can help you get your fish back on track!

From :

If you are having disease problems, then I hope this will help.

Small white spots on fins or skin:White spot (Ichthyophthirius)
Fine peppery coating on fins or skin Usually Yellow and moving:Velvet (Oodinium)
White or Grey Fluffy patches on skin:Fungus (Saprolegnia or Achlya)
White or Grey Fluffy patches on mouth:Mouth Fungus (Columnaris)
Pale skin as if from beneath skin layer:Neon Disease(Plistophora)
Red to Black nodules under skin igenetic Flukes(Metacercariae)
White to Grey nodules beneath skin:Tapeworm Larvae(Cestoda)
Cloudiness on surface of skin:Costia,Chilodonella,Trichondina, Ph extremes
Red Streaks on skin:Red Pest (Bacteria)
Destruction of Tail or Fins:Fin Rot (Bacteria)
Ulcers on skin:Red Pest or Ichthyosporidium
Black to Yellow nodules on skin or below:Ichthyosporidium
Protrusion of Scales, Bloated body: Dropsy (Aeromonas)
Protrusion of Scales often Red, NO Bloating of body:Infection of scales and skin (Bacteria)
Pop-Eye (Exophthalmus):Gas Embolism, Copper, Various Diseases
Cloudiness of Eyes even Blindness:Toxins, Severe White Spot or Velvet
Holes in Head, Ulceration of Lateral line:Hexamita
Crustaceans on skin:Argulus, Ergasilus, etc etc
Flukes on skin or gills:Gyrodactylus etc etc
Worms hanging from Anal passage:Nematodes
Nodular white swellings on body and fins:Lymphocystsis (Viral) Glugea, Henneguya (Sporozoans)
Spinal Deformity: TB,Genetic,VitaminDeficiency, Ichthyosporidium
Glancing off rocks or plants:White spot, Velvet, Toxins
Fins Clamped:White spot, Velvet, Toxins
Loss of Balance, Sluggish movements:Tank too cold, Trynoplasma
Severe loss of balance, belly up:Swim Bladder disease
Gasping at surface xygen deficiency, excess Co2,Too hot, Toxins
Jumping out of waterh extremes, Toxins
Unusual Colour of skin, usually dark:Ichthyosporidium, Toxins.

White Spot (Ichthyophthirius)

A parasite that we will all encounter whilst keeping fish.
As an adult it is embedded in the skin of the fish causing irritation, your fish will probably be glancing off rocks and plants to alleviate the itching.
The parasite will feed and grow on the blood and skin cells of its host for a few days until it is fully grown.
It then bores its way out of the skin and drops off into the substrate, it then forms a cyst which then goes through rapid cell division until about 1000 young are released into the water to start the whole process again.
The whole process takes just five days at 27C.
There are cases where the parasite actually lies dormant in the skin of the fish and will not emerge until it is ready, making eradication quite difficult.
The best time to kill them is when they are free swimming and looking for a host.
Treatment must be external and aimed at the free swimming stage hence the need to dose again after a few days, suitable cures are widely available.

Velvet (Oodinium)

Velvet is caused by a dinoflagellate, classified by some as an alga because it carries Chlorophyll.
There are two main species, Oodinium limmneticum and Oodinium pillularis.
The free swimming stage of Velvet settles on the skin and gills of the fish,
adhering at first by its long flagellum, later putting out pseudopodia, (similar to fingers) that penetrate the skin and give it a very firm grip.
Velvet has a similar life cycle to White spot, feeding and becoming a cyst it produces upward of 200 young before dropping off.
The appearance is similar to gold or brown dust over the body and fins which at times may appear to move.
Symptoms are similar to White spot, glancing off rocks etc.
As Velvet is highly contagious it is important to eradicate this problem as soon as possible.
Treatment is aimed at the free swimming stage and there are good cures available from your local store.
Copper sulphate can be used at a concentration of 0.2 mg per litre or 0.2 ppm.
This should be repeated after 3 days to ensure eradication.

Fungus (Saprolegnia or Achyla

FungI are in fact colourless plants, they are very diverse in in form and have not been studied that much in fish.
Saprolegnia and Achyla are genera of fungI that attack weakened and injured fish, usually settling on damaged skin or gills, they will also attack the eggs of fish.
The spores enter the aquarium from the air so there is no way to stop possible outbreaks.
Threads of fungus spread under the skin forming a web like structure and eventually produce tufts of external hyphae that may be large enough to look like cotton wool.
These form spores that become free swimming and can then go on to infect other fish that are weak or injured.
It is important that you remove any fish you suspect immediately to a hospital tank for treatment
Symptoms of fungus are a grey or whitish growth in the skin of the fish, often associated with visible damage.
Treatment can be with Malachite green in a separate tank for 30 seconds at a strength of 60 mg per litre, repeat treatments may be necessary.
The fungus is stained by the Malachite and usually drops off within a few hours.
Keep the fish under observation for 2 or 3 days as fungus can sometimes regrow.

Mouth Fungus (Columnaris)

Although Columnaris resembles fungus it is in fact a Bacterium.
It is usually found just around the mouth area, rarely spreading.
The first signs are a thin white line around the lips, which then grows into white or grey short tufts that resemble fungus.
Early treatment is needed if you are going to save the fish?s life, due to the toxins released and the fact that the fish can not feed.
The best and most effective cure is to use Anti-Biotic.
Penicillin is very effective at 10.000 units per litre, with a second dose after two days.
Remember to remove all filtration whilst dosing to avoid killing the beneficial bacteria.

Neon Disease (Plistophora)

Named after the fish that it was first identified in, but this problem can affect all other tetras and it is now known to affect other species.
The organisms lie in the muscle tissue in the form of cysts which burst and
release spores, the spores then bore deeper in to the muscle and then repeat the process.
Eventually some of the spores will reach the water, probably via the gut, these then go on to infect more fish usually by ingestion.
I personally think the best way to control this is to humanely kill the infected fish as there is no reliable cure.

Digenetic Flukes (Metacercaria)

Typically seen in newly imported fish and in two forms.
Black spot is caught from snails that release the Cercaria.
Larval forms penetrate the skin and encyst in the tissue and may be seen as red or black nodules.
If eaten by a Bird for instance they then develop into adults.
Sanguinicola disease passes from fish to snail and then back as minute worms that live in the fishes bloodstream.
There they lay eggs that block up the blood vessels which in turn causes
As far as I know there is still no cure for this problem.

Tapeworm Larvae (Cestoda)

Not commonly seen in fish but can be introduced in tubificid worms as food.
They then become adults in the gut of the fish usually about 3mm in length.
Not seen very often in the aquarium but if seen there are commercial cures available, best to consult a Vet.

Skin Cloudiness


Costia necatrix is rather rare in aquariums but if seen as skin cloudiness is easily eradicated by raising the temperature to 32C, otherwise treat as Velvet.

Chilodonella, Trichodina

These actually sits on the skin and are more easily eradicated.
Usually spotted by the fish glancing off objects, clamped fins and usually gasping at the surface as the gills are usually infected.
Treat as Velvet.

Ph Extremes

Ph extremes can cause all sorts of problems.
Gill will be injured and there is usually cloudiness of the skin due to mucus
being shed this is accompanied by the fish gasping at the surface and mad dashes around the aquarium.
TEST immediately and if necessary rectify the problem.

How exactly do you rectify the problem?
Change water immediately. Remove fish to a neutral PH if possible
-Hard water- mix with distilled or r/o water
-soft water- add a source of calcium to the filter to increase KH( i.e. crushed shells)

What are the extremes?
-Depending on what fish is kept, but below 5.5 above 8.5 (except some cichlids and marine)

Possible causes?
Too much Co2 with little KH to buffer causing a ph crash or Ph to sink below 6.
Taking fish from one range of Ph to another that is too drastic.
* From 8 to 7 is not as bad or harmful as 6 to 7. The acid side is much more sensitive to fish.
*always properly acclimatize fish to your water.

Red Pest (Bacterial)

Red pest is so called because of the red streaks that occur on the skin, that may lead to ulcerations, and fin or tail rot, that can lead to parts of the fins or tail
actually dropping off.
This bacteria infects the fish internally and externally and treatment is not
usually effective.
If fish are only lightly infected you can try to eradicate this problem by
sterilising the aquarium with Acriflavine or Monacrin.
Giving the aquarium a good clean up is also helpful, feed lightly whilst treating.
Personally I would not bother with treatment as by the time you notice this
bacteria it is usually well advanced, and the fish are already suffering.

Fin Rot (Bacterial)

Usually the secondary stage of Red Pest (above)
If the fish reaches this stage then you will have to use Anti-Biotic to eradicate.
Remember to remove all filtration as the Anti-Biotic will kill the beneficial bacteria.
-discoloration of the fins in early stages may go unnoticed)
fins become ragged and frayed
Terminal stages, only shreds of the fin or tail remain
- can lead to secondary fungus infections

Causes- Several bacteria can cause it.
-Improper maintenance routine.
-Infrequent water changes.
-Temperatures too low for the fish being kept

Danger- Highly contagious


This fungal disease is widespread attacking the liver and kidneys and pretty well everywhere.
Infection begins via food and the parasites infect the blood stream, settling down as brown cysts.
These then grow and produce daughter cysts by budding or by the mother cysts bursting and releasing the young.
The symptoms depend on what part of the body is infected.
Fish may become sluggish, show hollow bellies, lose balance and eventually external cysts and sores, by this time it is usually to late to save the fish.
Treatment is difficult but treat as for Saprolegnia.

Pop-Eye (Exophthalmia)

Pop-eye may not be caused by infection and there are various causes.
Easily identified by the protrusion of one or both eyes.
It is commonly caused by excess gas in the system brought about by
Super saturation of gas in high pressure water mains.
It can also be associated with Dropsy or Ichthyosporidium.
Look for bubbles of gas in the eyes, this indicates the bends, as does nervous upset, distress or just odd movements.
If these signs are obvious then lower the temperature slowly to increase solubility of the gas (usually nitrogen) reduce aeration and wait to see if there is any improvement.
In marine aquaria Copper poisoning can be one of the causes.
Pop eye can also be caused by hormonal imbalance for which there is no cure.


If in doubt as to what is wrong always suspect Toxins, try and remember if you have used anything toxic in the room or introduced them on your hands or equipment.
Immediately begin partial water changes of up to 50% at a time to reduce the problem.
Cloudy eyes, Bloody patches and listlessness indicate metallic poisoning.
Copper pipes, Galvanise (Zinc plating), Cadmium or Nickel.
Other possibilities are Chlorine and Chloramines, use a good water preparation aid.
Above all keep the aquarium clean and tidy and you should avoid toxins.

Hexamita (Hole in the Head)

Usually associated with Discus this Flagellate will in fact affect other fish
particularly large cichlids.
Hexamita infects fish by ingestion with food and begins life in the gut.
Infected fish will usually appear thin in the stomach and may have sores or ulcers around the head.
A bad case looks as if someone has chiselled out holes in the head.
It is said by some that this will cure itself by generally cleaning the aquarium and paying extra attention to cleanliness and good quality water changes.
There are cures available from your Local fish store.

Argulus, Ergasilus Etc

Fish lice (Argulus) are in fact a small crustacean that attaches itself to its host and then proceeds to feed on its blood.
It is thought that they can transmit disease so should be removed quickly.
On large fish this can be done with forceps, unless you have a mass infestation.
Potassium permanganate in a hospital tank at 10 mg per litre for 10 to 30 minutes is effective.
Or alternatively you can use insecticides but I am not sure about the use of insecticides in the aquarium.
I personally would try a salt bath first to see if they drop off.
If in doubt ask you Local fish store.
Ergasilus is also a crustacean that affects the gills of fish.
Try the above cures or ask your LFS.
Gyrodactylus Monogenetic Flukes

In fact a flat worm that in the early stages can be mistaken for white spot.
They infect the gills and skin of their host and produce live young.
Symptoms are pale skin, drooping fins, rapid respiration and even emaciation.
Treat as for Argulus, Potassium Permanganate or alternatively use Formalin but only in a hospital tank, use 2 ml of 40% solution per 10 litres for 45 minutes.
Salt bath at 15 gm per litre for 20 minutes may also work.


These threadworms will infect all parts of the body but are only seen when hanging from the anus of the infected fish.
Consult your LFS or personally I would consult a Vet.
There are theories that threadworm treatment for cats can be used mixed in with food, but I do not know the amounts needed.


A viral disease that causes the host cells to swell up giving rise to tumours, that almost look like spawn (granular) attached to the body and fins.
There is no guaranteed cure so it is probably best to dispose of the fish

Glugea, Henneguya

Sporozoans that form large cysts that look similar to Lymphocystsis and is also incurable, dispose of the fish humanely.


Symptoms are Hollow belly, Knife back, Pale skin, Bending of spine.
They also lose their appetite which does not help them.
If suspected it is best to dispose of the fish immediately.
TB can be passed on to humans but only if you have open wounds on your hands when placing them in the aquarium.


As with all other animals genetic defects can take all forms, Bent spines, No tail or fins Etc.

Vitamin Deficiency

This can also cause abnormalities similar to TB and Genetic defects.
Lack of Calcium and Vitamin C are the two main culprits, resulting in bent spine and abnormally small fish.

Tank too Cold or Hot

Chilled fish will crowd together or stay motionless on the bottom.
Sudden chilling will cause Shimmies and disease.
Hot fish tend to dash around the tank, gasp at surface and even try to jump out.
The answer here is obvious.


Sleeping sickness infects the blood just as it does in humans.
Infected fish are drowsy, may swim strangely and become thin.
It is usually seen in pond fish that have been recently moved into an aquarium.
I think it is brought on by warming up the fish too quickly.
There is no cure.

Swim Bladder Disease

Mostly seen in fancy goldfish it is not so much a disease as a genetic abnormality caused by mans fascination for odd shaped fish.
The end result is that they get wind trapped in their stomachs which they cannot get rid of.
An old cure was Epsom salts.
The other problem is their swim bladder is in the wrong position and the fish is constantly fighting the effects.
Swim bladder disease on the other hand can affect all fish.
Raising the temperature and adding salt at 5 gm per gallon seem to help.

Oxygen Deficiency, Excess Co2

Similar symptoms, including gasping at the surface and irregular respiration.
Check the Ph, this will indicate which problem you have as Co2 excess can only occur at low Ph.
It is more likely to be O2 shortage, aerate water well and perform partial water change.
Dropsy (Aeromonas)

Dropsy usually takes one of two forms, body swells due to fluid accumulation, which causes scale protrusion, and also protrusion of the scales without the body swelling up, false dropsy.
Dropsy is caused by a bacterial infection of the kidneys and other internal organs, causing fluid accumulation or even renal failure.
Treatments are varied, adding salt at a rate of 5mg per gallon seems to help.
With modern Anti? Biotic this problem is soon cured.

Infection of scales and skin (Bacterial) Treat as above.

How to avoid Problems

All in all the better your maintenance regime, the better your chances of having happy healthy fish.

Keep all equipment clean.
Do not over clean filters.
Feed sparingly.
Perform good quality water changes regularly.
  • Thread Starter
  • #3
Thanks for the quick reply & the warm welcome, this is my first time using a forum... I'm just kinda desperate to figure out what's wrong with him... At first I thought it was an ulcer, but it doesn't look as nasty as that... before it had a whitish/cloudish substance around the red bump but its gone now. I read through your list but I still can't tell what it is *sigh* I just spotted the mark today so I'll monitor it and see how it is tomorrow morning.

Thanks again =)

s2 reiI

O btw, he also has somehow broken his fin, is there anything I should do in particular to help heal that?
Poor guy hehe we nicknamed him monster because he's so tough, he's survived through everything and all of sudden he has this bump and a broken fin...
  • #4
Looks like a infected area from an injury.
Your best course of action is to do a largeish water change of about 35%.
Do another 35% change 48 hours after the first one.
What is the size difference between the two ctafish and are they the same species?
When catfish or most other fish squabble, it is best to add more hiding places.

Hope this helps,
  • Thread Starter
  • #5
The large catfish is about 11-12cm, whereas the small one is about 3-4cm and yes they are the same breed... its harder to catch a good look at the small one because she swims really fast. She has a pretty good hiding spot but I might find a little pot for her to go into.

I did a big water chage yesterday when I noticed the bump... So I'll take your advice and do another one tomorrow as well.
Saw the bump today and still looks the same, hasn't gotten any worse or better... so do you think that the broken fin and bump will heal itself? I don't need to get anything?

Thanks a lot =)

  • #6
I feel that if you continue this water change schedule for 4-5 more times, will be more helpful than medications.
While medications do have their place, in many cases, I feel largeish water changes are a better way to deal with problems.

  • #7
The fin should grow back as long as you maintain good water quality.
  • Thread Starter
  • #8
Thanks a lot I'll keep repeating the water changes then =) I get abit nervous whenever a fish gets sick because, for me, unfortunately they never make it, especially when I use meds. (maybe I just don't make a very good fish nurse) =P

Thanks again,
I'll update you with how he's going at a later date, but if any other ideas pop up on what it could be... feel free to tell me

  • Thread Starter
  • #9
umm... will the fin heal back together? It's more like a rip?
but yes I will check the water regularly and make sure it is in a good condition =)


  • #10
Yes it will heal back together, as long as the water quality is very good. (sorry that's like the 10th time we've said thet ) If it gives you peace of mind, one of my Otos had really bad finrot and his tail fin was eaten away down the middle (basically split in half), but now he is just fine and it grew back nicely.
  • Thread Starter
  • #11
Thanks =) I feel a little more relieved... lol I've never worried so much over a fish, I'm obessed and have been checking this forum continously (and I have never turned to a forum for help) I think its because this one is usually so tough and I've had him for years, and trust me he has survived through many many plagues and the massacre of 2002 hehe and if he didn't make it now I would feel like such a horrible carer.
Thanks for all your speedy replies and you can repeat all you want... gives me no excuse to forget then =P


This forum is awesome (o^_^o) b
  • #12
I don't blame you for being worried, we all love our fishies. I hope he gets better!
  • Thread Starter
  • #13
sadly my little monster died *cries*
I'm still not exactly sure what it was, but now the smaller one seems to be getting the same symptoms, maybe its a parasite? The small catfish had a small white fungus looking spot and now its a red/pink one (looks like raw flesh) - what the big one had...

*sigh* hopefully it would end the same.
  • #14
I am so sorry! If it looks like tufts of cotton and some redness, put your fishie in a hospital tank and start treating right away with Maracyn I and Marcyn II together. Hopefully this one can be saved. Keep us posted.
  • #15
Sorry about your fish :'(
  • Thread Starter
  • #16

I've actually started a new tank, since I don't have the big catfish anymore I've gone for a smaller one. The little catfish seems to be alright so far, but I guess I shouldn't be speaking so early. Sorry I've never heard of "Maracyn" do they sell it in Australia? I've been recommended a medication called "melafix" apparently it's good for open wounds, smells like eucalyptus hehe well I just started the treatment today, so I'll keep you posted =)

Thanks again guys
  • Thread Starter
  • #17
Hey guys,

Yeah the little catfish seems to be much better, all the symptoms have reversed went from raw pinkish looking flesh, back into the white sort of fluffly spot, to a now flat white spot (but I 'think' her skin is growing back on top of it) The "Melafix" worked =) I'm still using it though.

Keep you updated on if it heals back properly or not

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