unexplained sudden silver shark death....

[nicole]

one of my beautiful 7" Silver Sharks (balas) died unexpectedly last night. It was the (suspected) male, the youngest, just over a year ago since i got him.

it was about 9:30pm and all of a sudden he rose to the surface (nose first so he was vertical) then skitted around hysterically in circles (still vertical with nose up) for about 30 seconds, then sank to the bottom, totally upsidedown. he never did regain his correct balance, his fins were erect and he was laying there, resting on the bottom totally upsidedown. his gill covers went yellow tinged (sign of stress) and at one stage his head colour turned quite dark.

well, the shark did not improve and was getting weaker and looked in allot of pain, so i decided to put him out of his mysery, the hardest thing i have had to do in a long time. to me, a small fish dying is one thing, but a large, much loved fish is so much more horrible.

has anyone seen this kind of death before?
I was wondering if it were possible for the swim bladder to have burst? or another internal organ?
just the way he was behaving and there being no prior signs, it seems the death was caused by something internal busting or some kind of fit? he was a very healthy fish, then this....

please help if you can, i would like to find out if possible what happened to my beautiful shark...


i will post a little info on my tank, although with this kind of death, i do not belive the conditions of it were a factor, if you think you need to know anything else, please ask..
125G tank
26oC, ph of 7.0-7.4
good filtration, regular weekly maintenance
tank mates:
1x Gold Severum
4x Angel fish
2x Silver Sharks (now 1)
1x Black Ghost Knife
3x Zebra Danios
3x Bristlenosed Catfish
1x Red Tailed Black Shark
10x Hockeystick Tetras
10X Head and Tail Light Tetras
2x Bloodfin Tetras
4x Clown Loaches

[David]

hi nicole

sorry to hear this.....yes its happened to me before and it sure sounds like a swimming bladder disorder which could be due to injury....how it happens is sometimes a mistery....but most of the time it is usually conflict with other fish or injury itself thru blind fright charging.

I pretty much doubt that it is your water condition.......

[Mez]

Sounds to me like something internal. Like something split/burst..
Maybe?
Is very weird..
David, i dun think swim bladder dissorder can cause death of fish within a day...friend of mine had a goldfish that lived for ard 3 years with a faulty swim bladder...
Just my thoughts,
James

[David]

which was why my guess would be either a tank fight or fright.....

[nicole]

noting seemed to happen beforehand to bring this on, there was nothing to fight with and he did not get startled and bang into the glass or anything. we saw it happen from start to finish (it was quite horrible to watch).
i am at this stage putting it down to some internal organ failure, disorder, damage or a tumor bursting or something.
i have seen fish with a swim bladder disorder, and as already said, it is not so sudden. i didnt think this was swim bladder, unless it totally burst (but i have since been told "Swim bladders are like a smaller extremely porus ball so they are not like a sack or anything that can be burst&quot as, as far as i know, fish with a swim bladder problem will generally float and have loss of balance to the side and not be in this kind of sudden pain..

anyway, thanks for the replies so far..

[David]

hey nicole

any change in fish diet, filter washing, or by any change any household chemical got into your tank....ie mosquitoe spray .......?