I lost one of my danio's :(

[fishy_sean94]

So yesterday afternoon I was about to feed my fish and noticed that one of my Danio's was swimming very oddly and also had a few "white patches" on him.
I hadn't noticed anything strange with him earlier in the day or the previous night while feeding.

Here's a video of him swimming stranglely and you might just about see the white bits I mentioned.

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It all happened very fast and within about 20 minutes he had completely vanished in the tank. I spent about 45 minutes trying to find him to no avail. I assume his own brothers along with my Amano shrimp ate him .

After this I did a water test and things were fine/normal except Ammonia was at 0.50 which I assume is due to the dead fish. I added some Prime to detoxify it as I wasn't able to do a water change straight away, though have since done that today.

All my other fish and shrimp currently seem normal.

I was just wondering what it could've been that suddenly caused my two year old Danio to die like that? Was it just age or do I need to be worried about something that could also spread to my other fish?

 

[Slaphppy7]

IME, danios tend to be extremely overbred/inbred, and prone to disease & genetic defects.

If the other fish are fine, and water params good, I wouldn't stress over this loss too much.

@Colin_T may be able to add more info...

 

[Sgooosh]

it looks maybe to be a bacterial infection, cleaning the tank thoroughly will prevent further such as wiping deco or wiping tank
edit: it could be that the immune is ruined from inbreeding

 

[Back in the fold]

@Slaphppy7 I wonder about that inbred business. I used to really believe it but now I'm rethinking it. Other factors might be lack of culling out the runts and deformed fish and thus breeding inferior stock. Poor diet, exposure to too much or too many different aquarium chemicals and breeding fish too soon like they do chickens nowadays. This one is a head scratcher.

 

[Colin_T]

The fish has trouble swimming and is constantly floating up. Normally this can be caused by air in its intestine. The air is ingested when the fish eats dry food from the surface. However, the fish did not look fat or like it had eaten much so this is more likely an internal issue with the swim bladder.

The white mark on its back looks like a wound. It might have been bitten by another fish or got caught under something. This could have damaged the swim bladder or other internal organs and caused internal organ failure.

What other fish and shrimp are in the tank?

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An ammonia reading of 0.5ppm is a bit high for 1 small danio dying in an aquarium 30 minutes before testing the water. You might have an issue with the filter bacteria.

The ammonia in the water did not cause this.

How long has the tank been set up for?
What sort of filter is in/ on the tank?
How often and how do you clean the filter?
Have you added anything to the tank in the last 2 weeks?

 

[fishy_sean94]

The fish has trouble swimming and is constantly floating up. Normally this can be caused by air in its intestine. The air is ingested when the fish eats dry food from the surface. However, the fish did not look fat or like it had eaten much so this is more likely an internal issue with the swim bladder.

The white mark on its back looks like a wound. It might have been bitten by another fish or got caught under something. This could have damaged the swim bladder or other internal organs and caused internal organ failure.

What other fish and shrimp are in the tank?

------------------
An ammonia reading of 0.5ppm is a bit high for 1 small danio dying in an aquarium 30 minutes before testing the water. You might have an issue with the filter bacteria.

The ammonia in the water did not cause this.

How long has the tank been set up for?
What sort of filter is in/ on the tank?
How often and how do you clean the filter?
Have you added anything to the tank in the last 2 weeks?

Other thank mates are 5 Danio's (all 6 bought together 2 years ago), 4 Cherry barbs (added over a month ago) and 5 Amano shrimp (added last year).

The tank has been set up for a little over two years.

Filter is just the stock filter that comes included with the Fluval Flex. It's a sponge filter with carbon and ceramic rings.

On average I clean the filter once every four weeks. I do this during a water change and wash it in old tank water I've syphoned out.

And no nothing has been added in the last two weeks.

I'm not sure what could have damaged him as I hadn't been doing any maintenace that day to accidentally cause damage and I had never seen any of the fish fighting eachother.

 

[itiwhetu]

I'm sorry but sometimes fish just die for no reason. Don't panic. Be very careful what you add to your tank, you may just make things worse.

 

[Colin_T]

The fish might have got stuck under something, sometimes it happens when they are dashing about playing games. Or the fish might have just had an issue with its swim bladder and it finally popped. Either way there isn't much you can do about it or preventing it. Just keep the tank clean and well maintained and feed the fish a varied diet.

 

[fishy_sean94]

I realise some times these things just happen. I suppose as it was my first fish loss I just wanted to make sure it wasn't anything I could have prevented myself.

Thank you for the replies, I feel a bit better now as it seems there isn't really anything I could have done differently