Tail rot or other infection?

[Robmana]

Hi,

I have two Denison Barbs who have thrived for 7-8 months in my community tank. In the past two days one of their tails has discoloured and rapidly rotted down to the body, leaving one half in tact.

The fish, following a long period out of sight, is now swimming downwards vertically in the corner of the tank, a symptom, I suspect, of a more serious infection.

Can anyone shed some light on what this could be? I have applied both aquarium salt and Melafix in a desperate attempt to save the poor soul, but feel I may be fighting a losing battle.

Water parameters are perfect having done a 10% change on Saturday.

Any help would be great!

 

[Colin_T]

How much salt did you add?

A video of the fish swimming might offer information about that downward behaviour.

The white stuff on the caudal peduncle region (just before the tail) is covered in excess mucous.

What other fish are in the tank?
Has the fish been attacked?
Is there anywhere the fish might have been trapped and damaged its tail?

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I would normally recommend rock salt at a dose rate of 2 heaped tablespoons per 20 litres of water. Keep the salt in the tank for 2 weeks.

If you used that amount of salt and it didn't help, then a broad spectrum fish medication that treats fungus, bacteria and protozoan infections might help.


-------------------
Before you treat the tank, do the following things.

Work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

If you have big rocks or driftwood in the tank, remove these before measuring the height of the water level so you get a more accurate water volume.

When you measure the height, measure from the top of the substrate to the top of the water level.
You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" at the bottom of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating or it will adsorb the medication and stop it working.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate. The water change and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration when using salt or medications because they reduce the dissolved oxygen in the water.

 

[Robmana]

How much salt did you add?

A video of the fish swimming might offer information about that downward behaviour.

The white stuff on the caudal peduncle region (just before the tail) is covered in excess mucous.

What other fish are in the tank?
Has the fish been attacked?
Is there anywhere the fish might have been trapped and damaged its tail?

-------------------
I would normally recommend rock salt at a dose rate of 2 heaped tablespoons per 20 litres of water. Keep the salt in the tank for 2 weeks.

If you used that amount of salt and it didn't help, then a broad spectrum fish medication that treats fungus, bacteria and protozoan infections might help.


-------------------
Before you treat the tank, do the following things.

Work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

If you have big rocks or driftwood in the tank, remove these before measuring the height of the water level so you get a more accurate water volume.

When you measure the height, measure from the top of the substrate to the top of the water level.
You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" at the bottom of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating or it will adsorb the medication and stop it working.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate. The water change and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration when using salt or medications because they reduce the dissolved oxygen in the water.

Hi Colin, brilliant information. I felt I had to act quickly so I’m dosing Myxazin as prescribed in an attempt to stave off further degradation of the tail. I’m two days in to a five day course so planned to monitor progress in the hope that it cures the problem.

I will also follow your advice and undertake all those measures. The things you do to preserve the life of a fish, then eat Sardines for lunch!!

 

[Robmana]

Oh, on salt, only a couple of tablespoons. It’s a 125 litre tank, say 115 taking into account wood, filter etc

 

[Robmana]

I don’t think the fish has been attacked, generally peaceful fish in the community. The tail actually lost colour then started losing fin within 24 hours and now even the lower part has gone, so we’re down to the body.

Since adding Myxazin the fishes behaviour seems to have improved and I’ve also removed some plants which I felt were melting and could possibly have been a breeding ground for bacteria.

I’ve attached a picture of the tank

 

[Colin_T]

You need some floating plants for the gourami but wait until after you have finished treating the fish.

A dark picture on the back of the tank would make their colours come out better too.

 

[Robmana]

Great advice again! I did look at floating plants yesterday but wasn’t exactly sure why Inwas buying them!!

 

[Colin_T]

The best floating plant is Water Sprite (Ceratopteris thalictroides/ cornuta). It can get big but is usually around 5-6 inches across. Grows rapidly and can be planted in the substrate too where it turns into a lovely light green shrub. It's one of the best plants for livebearers, gouramis, Bettas and baby fish.

 

[Robmana]

Amazing, thanks Colin!

 

[Robmana]

You need some floating plants for the gourami but wait until after you have finished treating the fish.

A dark picture on the back of the tank would make their colours come out better too.

 

[Robmana]

You need some floating plants for the gourami but wait until after you have finished treating the fish.

A dark picture on the back of the tank would make their colours come out better too.