Corydora having difficulties swimming, body twisting and not able to float

[Flyer99]

Hi there everyone, I just have a situation happening with my corydora.

For the past week one of my corydora has been struggling to swim and cannot control its body movements. It will try and swim and will just fall on its back or side and stay there before trying again. Obviously my biggest concern is he is not able to eat. I try to drop food pellets right above him in the hops he can gobble one up. The situation hasn't gotten any worse since a week ago when I first noticed this, but I am wondering if he is hnugry or not at this stage. I think its a spinal injury or something physical, I don't think its a disease as he looks perfectly normal (no pine cone scales, puffy eyes, weird poo, swelling etc).
Im thinking if I should isolate him and put him in a fry net cage?


Water parameters (measured today)
PH: 7.4
Ammonia/Nitrite: 0
Nitrate: 40ppm (by the way my tank has always had high nitrates, my water is extremely hard. I use resin but it only works so much, so generally my tank has between 30-40 nitrates, but Ive always had it like that for 2 years)
Temp: normally 24/25 but recent heat wave in UK temperatures are more between 27/28

Water changes: around 40% every 2 weeks
No chemical treatments
Tank mates include 3 other corydoras and 2 guppies
All other fish normal

110 Litre tank

Filtered by seachem tidal 50, good/strong water flow
Co2 injected


Any suggestions welcomed as I hope this is something he can cure by himself if I just help him out a little.
I have captured a video, but it wont upload here, so if needed I can send that over.

Many thanks!

 

[Oblio]

The high nitrates are not helping matters. What is your tap water nitrate level?
If the level is high from your tap, you can reduce with terrestrial plants such as Pothos or Bamboo. It appears that your tank is cycled and has plants so that should reduce the nitrate coming from your tank. If the tap water has low nitrates, large water changes will bring down the ppm.

 

[Oblio]

I have captured a video, but it wont upload here, so if needed I can send that over.

Upload to Youtube and link to video

 

[Colin_T]

Upload videos to YouTube, then copy & paste the link here.

What sort of filter is on the tank?
How often and how do you clean the filter?

How often do you gravel clean the substrate?

What do you feed the fish and how often do you feed them?

 

[Alice B]

There is a swim bladder ailment I saw go from corydoras to corydoras back in the 1990s, loss of ability to balance, similar in all things except the twisting. I dosed the tank for ich with a quinine product that was available back then, (because I had introduced a fish with ich from the pet store) I think it was Clear Ich - mix powder with water, shake, darken tank, dose 3 days in a row and at the end of 3 days, the latest dying cory wasn't dying anymore. I still don't have a name for whatever it was but it responded to an anti-parasitic treatment.

 

[Flyer99]

The high nitrates are not helping matters. What is your tap water nitrate level?
If the level is high from your tap, you can reduce with terrestrial plants such as Pothos or Bamboo. It appears that your tank is cycled and has plants so that should reduce the nitrate coming from your tank. If the tap water has low nitrates, large water changes will bring down the ppm.

Hi Oblio, please excuse my late reply, I am so busy these days.

My tap water has very high nitrates I measure at 30ppm, and the water report from my water supplier says similar (31.2ppm)

I filter my water using the fish logic nitrate resin. I then on top of that have a rechargeable resin bag in the filter media tray, however even with all this after 2 days the nitrates always level off and stay at around 40ppm.

Which is weird as my other tank (although bigger) using the same technique manages around 15ppm...and it has more fish!

The corydora is still alive and well (in terms of physical appearance), but he keeps twisting his body, its not nice to look at as it must be uncomfortable.

 

[Flyer99]

Here is the videos I uploaded to vimeo, I hope you can see.
There are 3 videos:

 

[Flyer99]

There is a swim bladder ailment I saw go from corydoras to corydoras back in the 1990s, loss of ability to balance, similar in all things except the twisting. I dosed the tank for ich with a quinine product that was available back then, (because I had introduced a fish with ich from the pet store) I think it was Clear Ich - mix powder with water, shake, darken tank, dose 3 days in a row and at the end of 3 days, the latest dying cory wasn't dying anymore. I still don't have a name for whatever it was but it responded to an anti-parasitic treatment.

Thats very interesting to hear! It feels as if the corydora has lost ability in one side of his body to move it, it can only move one side and so it cant balance himself. The fact that it cant swim up, might indicate it also has something to do with the swim bladder. Im not comfortable adding any medication in the tank in case it affects anything else. I do have a small tank with just snails so could try that one, but is it worth making the corydora panic and possibly make it worse moving him to another tank?

 

[Flyer99]

Upload videos to YouTube, then copy & paste the link here.

What sort of filter is on the tank?
How often and how do you clean the filter?

How often do you gravel clean the substrate?

What do you feed the fish and how often do you feed them?

Hello Colin!

Sorry for late reply.

I have a seachem tidal 50.

I clean it every time I change the water because it gets clogged up with snails and debris from plants. I clean the filter case/propeller with tap water and I clean the media using the tank water.

I used to gravel clean about 1 year ago, but I do not touch the gravel now because its course sand. So really anything below it is trapped and I don't want to disturb it and possibly bring up poisonous gas (forget the proper name).


The fish/shrimp are fed Vitalis Catfish Pellets and JBL Novo Prawn, at 70% and 30% respectfully in an automatic feeder, I would say I generally feed on the lower side and twice a day (9am - 9pm). Occasionally I throw in some Hikari mini algea wafers

 

[Colin_T]

The fish has an infection in the brain (either protozoan, bacterial or viral). You can try salt but if there's no improvement after a few days I would euthanise it.

Is there blood on the side of the fish near the face?

-----------------
SALT
You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria, fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

 

[Flyer99]

The fish has an infection in the brain (either protozoan, bacterial or viral). You can try salt but if there's no improvement after a few days I would euthanise it.

Is there blood on the side of the fish near the face?

-----------------
SALT
You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria, fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

Hi Colin,

I have had a good look and there is no blood at all on any part of the fish. Theres probably many reasons why, but I am curious as to why this particular corydora has suffered this, I have never seen this before with any of my fish ever.

I do have aquarium salt with me from Interpet. I think I will give that a go, I used it a few times for a mollie that was beginning to have signs of dropsy but it didn't help, but there is no harm in trying here. I will do it tonight.

Thank you!

 

[Colin_T]

Infections in the brain are normally caused by a dirty environment (dirty gravel and filter, lack of adequate water changes). The weaker fish usually develop them first and then other fish get the problem.

A big gravel clean and water change, along with cleaning the filter, and adding some salt will usually stop it spreading but once the fish has started spinning, they don't normally survive.

The other possibility is the fish suffered a head injury or had a stroke. There's no cure for either of these issues so if there's no improvement after a few days with salt, put the fish down.

 

[Flyer99]

Hello again,

Over the weekend I have put 200g of aquarium salt. My aquarium holds around 90 litres of water with displacement, its about 70g less than recommend on the box. I will see if theres any improvement over the week, and if not I will put the fish down, as it is upsetting me that the fish has this terrible problem.

Do you recommend clove oil to be the best way?

Thank you

 

[Colin_T]

clove oil is easiest for most people, or wrap the fish in a paper towel and hit it on the head with something solid. But that gets messy so clove oil is probably best.

 

[AdoraBelle Dearheart]

Hello again,

Over the weekend I have put 200g of aquarium salt. My aquarium holds around 90 litres of water with displacement, its about 70g less than recommend on the box. I will see if theres any improvement over the week, and if not I will put the fish down, as it is upsetting me that the fish has this terrible problem.

Do you recommend clove oil to be the best way?

Thank you

I'm really sorry about your fish... when I saw the spinning I had to agree that it's a problem in the brain. He can't orient himself. He also looks a bit on the skinny side, a bit pale, and was panting hard in one of those video clips after he tried to move, poor little dude. I would also think euthanasia would be kinder at this point since recovery is unlikely. I'm really sorry.


I agree with Colin that either a very quick and hard, solid blow to the head can be a quick and almost instant death for a fish, but it's also a very hard thing to do, and many people would not be able to bring themselves to do it. Clove oil is a very humane way to euthanise a fish, when done right.


The method with clove oil is to mix just a small amount into a container that you will then add the fish to. Use something you can dispose of, not a tank or container you normally use for your fish. The aim is to sedate the fish first. People use clove oil to sedate fish for operations, before waking them up again by removing them from the low level of clove oil and then holding the fish in the filter output for clean fresh oxygenated water to flow through the gills, slowly waking the fish up again. So we know that clove oil used in that low amount will knock the fish out, basically. To euthanise, you use the small amount first to sedate the fish, then add a lot more clove to the water the fish is in, overdosing the fish and stopping the heart. You can leave the fish in the clove oil water for a while to make sure it has passed away before burying/disposing of it (never flush fish down the toilet though - bury or bin).

Some people go wrong with clove oil by using too much too soon, sending the fish into a panic. You want them to be sedated first by adding it gradually. Since oil doesn't mix well with water, I add some tank water to a different container with a lid, shake it well then gradually add some of that to the tub before adding the fish, gently stirring it in. I think that way the fish gradually ends up going to sleep as droplets of oil pass over the gills. Once movement and breathing slows, check if the fish is awake by gently moving it with your finger. If it doesn't try to swim away and just kinda floats/sits there, it's sedated and you can shake up the oil mix again and add more to the fish container.
These videos can be helpful;