Pale, Gasping Fish

[littlest]

OK, I had four dwarf pencil fish in a 10G tank for a bit under a year. Back in October one of the pencils 'disappeared'. Never found a body. The other three seemed fine, I checked tank parameters - all fine.

Then, about two weeks ago I came home to find another pencil dead. I had been away over the weekend so wasn't there to see if he had any symptoms before he died. I check the tank parameters and nitrite was a bit high (under 0.25 but more than zero). I did a large water change, and stepped up my water changes to twice a week (I was checking parameters regularly and all were fine from the day after the death).

I also kept an eye on my remaining two fish and saw no symptoms.

Tonight I came home and found the smaller one 'hiding'. He's pale (he is wearing his night-time colours despite the lights being on - dwarf pencil fish change colours/patterns at night). He is also 'gasping' - basically opening and closing his mouth a lot. The other (bigger) pencil fish is showing no symptoms but was chasing/hassling the sick fish (who still seems fast when approached) so I've put the sick fish in a breeding net. The sick fish is also looking a bit raggedy around his fins (possibly by being nipped by his tankmate).

Anyway, I'm not sure what to do now. And what I should be treating for?

Tank size: 10 G
pH: 7.4 (same as tap water - it's always been this level)
ammonia:0
nitrite:0 (has been 0 since two weeks ago - when it was somewhere between 0 and 0.25)
nitrate:20
kH:
gH:
tank temp: 26C/78F

Fish Symptoms (include full description including lesion, color, location, fish behavior): Pale - wearing night-time colours despite light being on, 'hiding', gasping - opening and closing mouth a lot, raggedy looking fins, slightly clamped fins

Volume and Frequency of water changes: at the moment twice a week - before 2 weeks ago it was about once every 2 weeks. Normally about 40 per cent

Chemical Additives or Media in your tank: Prime dechlorinator. For a couple of weeks I used another dechlorinator (API something), switched back to Prime about a month ago.

Tank inhabitants: 2 x dwarf pencil fish (originally 4)

Recent additions to your tank (living or decoration): none

Exposure to chemicals: none that I'm aware

 

[WILDER]

How long did you you have the nitrite reading as it can take it toll on fish.
How old is the fish.
Laboured or heavy breathing can be many things from parasites, bacterial, toxins in water, overdose of meds.
Any signs of flicking and rubbing.
Any excess mucas on the body of the fish.
Do gills look pale with excess mucas or red and inflamed.
Does the fish lay to oneside when resting.
Does the fish look bloated.

 

[littlest]

How long did you you have the nitrite reading as it can take it toll on fish. - I got the nitrite down to zero within a day, but it had been at least 2 weeks since the last time I tested the water, so it may have been above zero for as long as nearly 2 weeks or it may have been at lot less time than that.
How old is the fish. - I bought the fish about 10 months ago I think. Don't know how old it was when I bought it (it was from my lfs). I looked up life expectancy of dwarf pencil fish before and it said 1-5 years, which is a pretty big range and not that helpful.
Laboured or heavy breathing can be many things from parasites, bacterial, toxins in water, overdose of meds.
Any signs of flicking and rubbing. - no signs of flicking or rubbing
Any excess mucas on the body of the fish. - no excess mucas - the fish just has it 'nighttime colours'
Do gills look pale with excess mucas or red and inflamed. - I really can't see the gills on a fish this small sorry, it's only an inch long
Does the fish lay to oneside when resting. - No, it's staying upright, mid-water
Does the fish look bloated. - no, if anything a little thin, but he was always the runt of the 4

The fish is basically opening and closing its mouth constantly (like with every breath). which makes me wonder if it is a problem with its gills?

Also, it ate last night, and was seeming a little more active, but the same problems are persisting this morning. The other fish is still not showing any symptoms.

Thanks for your response Wilder. I hate situations like this because I want to do something, but I don't want to treat without knowing what it is.

 

[WILDER]

Dosn't sound like a parasite involved then.
It could be bacterial.
How thin is the fish.

 

[littlest]

It doesn't look wasted-thin or anything. It's belly doesn't go in. He is the smallest of the four I had (both in length and width).

He has his colours back a bit tonight, though still a bit paler than normal, and he is swimming about a bit more, but still 'gasping' (by the way, when I say gasping, I don't mean he is gasping at the surface. He is just opening and closing his mouth constantly).

Looking at him closely I am a bit worried he may be pine-coning. It is very subtle but the line of his back just doesn't look quite as smooth as it should. I'm really not sure if it is pine-coning or not. I had a betta who had dropsy once and the pine-coning was really obvious. I came home from work and he had completely blown up. He was dead the next morning.

Do the other symptoms tie in with dropsy at all?

 

[WILDER]

Signs of a bacterial infection when no symtoms are being pale or darker in colour, being listless and lathagic. Heavy breathing sometimes. Unable to get off bottom or top of the tank.
The thing is the med could finish him off, but it worth a try as long as you increase aeration.
Can you issolate for treatment.

 

[littlest]

I can't isolate him in a cycled tank. I have another tank mid-cycle. I already took some media from the tank the pencils are in to cycle the second tank, but it didn't work for whatever reason, and I am reluctant to take any more media from the current tank as I had a nitrite spike recently.

If it is bacterial shouldn't the whole tank be treated anyway? I mean, if there is bacteria in the tank then the other fish would be at risk too wouldn't he? Or doesn't it work like that? Would the meds harm the other fish too?

If I were to treat, what meds would you recommend in the UK?


(thank you so much for your help by the way)

 

[WILDER]

Anti internal bacteria med by interpet.