Frantic Cichlid

[Maria]

I have an established cichlid tank (6 yrs) with 4 Convicts about 8-10
years old, to which I added 4 young African cichlids (2 Red Zebras, 2
Blue). The next day I saw one of the blue ones suddenly flip out and
start darting around the tank completely out of control, then it calmed
down. The next morning it was dead. I then watched the other fish for
most of the day and they seemed fine, then in the evening one of the
other blue ones who had been normal up to that point suddenly went
berzerk, zooming, spinning, bashing into everything in the tank, then
it calmed down. Then in a snap it repeated the frantic darting until it
knocked itself out. Then it recovered, then did it again and again
until it killed itself. This took 20-30 minutes. I've never seen this
before. I checked the water chemistry, temperature, filter, everything
was fine plus I know the other fish hadn't been harassing them. The
fish had no signs of visible disease, no discoloration, they looked
perfectly healthy. So I don't know why this happened. Does anyone know
what it can be, or have any advice? Thank you.

[NetMax]

"Maria" > wrote in message
oups.com...
>I have an established cichlid tank (6 yrs) with 4 Convicts about 8-10
> years old, to which I added 4 young African cichlids (2 Red Zebras, 2
> Blue). The next day I saw one of the blue ones suddenly flip out and
> start darting around the tank completely out of control, then it calmed
> down. The next morning it was dead. I then watched the other fish for
> most of the day and they seemed fine, then in the evening one of the
> other blue ones who had been normal up to that point suddenly went
> berzerk, zooming, spinning, bashing into everything in the tank, then
> it calmed down. Then in a snap it repeated the frantic darting until it
> knocked itself out. Then it recovered, then did it again and again
> until it killed itself. This took 20-30 minutes. I've never seen this
> before. I checked the water chemistry, temperature, filter, everything
> was fine plus I know the other fish hadn't been harassing them. The
> fish had no signs of visible disease, no discoloration, they looked
> perfectly healthy. So I don't know why this happened. Does anyone know
> what it can be, or have any advice? Thank you.


Environmental shock is not that their conditions are not good, but their
conditions are sufficiently different from what they were last acclimated
to. As an example, if these fish came from an extremely hard water, and
your water is very soft, then their gill cells would literally be
exploding from the difference in osmotic pressure. Their frantic
behaviour could be instinctual "get out of here", without them really
understanding why.

There are other possibilities (pathogens) but my guess is water shock.
Verify by comparing your tank's pH and gH to where they came from.
Salinity can also be a contributor which would show in a TDS test but not
a gH test, so you might inquire about that. Compare the NO3 levels as
well, as NO3 shock (greater than 40ppm) will kill smaller fish, and
stress larger fish. Your tank conditions might be so much 'cleaner' as
to kill some fish. hth
--
www.NetMax.tk

[Maria]

Thank you for the advice, NetMax.
-Maria