Zebra Danio
with growth? on side 9/23/07
Hi,
I have an approx 35-40 gallon tank-it's one of the tall 6 sided ones. I
inherited it from a business I purchased a little over a year ago, and
ended up moving it to my house. It came with a few swordtails, and I
added 3 zebra Danios about a year ago. Two swordtails died three or four
months ago, I had calculated they were at least 2 years old, and
possibly as old as 4 according to an employee so I assumed it was due to
old age. There was 1 swordtail left and the 3 Danios, and we added 3
Cory cats. Nothing else has been added in the last 3 or 4 months.
There's a hang-on filter as well as a long airstone in the bottom, and
there's a really thick gravel layer. I vacuum the gravel and do about a
30% water change every few weeks- I know it's pretty lightly stocked so
confess I haven't been too terribly obsessive about this. I have not
added more fish as I have been pretty busy and didn't want to upset the
balance in the tank as everyone had been settled a while.
Last week, the last remaining swordtail died. I know she was only about
a year old as she was a baby when I inherited the aquarium.
She acted fine, then one day I noticed her hiding in the plants,
(plastic plants) next morning was dead.
Last night, I noticed one of the Danios has a horrible growth? sore?
something on his side. It looks for all the world like his intestines
are spilling out of his side. Last night it was red with a white spot on
the top, like a pimple. Today the white spot is gone. He was swimming
and schooling normally last night, but today is at the bottom in the
plants, hiding. The other fish are acting fine.
Please advise on how I should try to treat him-is it some sort of
parasite? I tried all sorts of searches but couldn't find anything. I
don't have a quarantine tank or extra filter but could put him in a
bowl, or something similar.
Sarah
<Sarah, without a picture it is impossible to safely identify this
disease or problem. From the sounds of things -- where you are seeing
internal organs pushed against the skin -- it sounds like a tumour or
cyst of some sort. These are relatively uncommon in aquarium fish, and
there causes are various. There is no cure, and generally the best
situation with very small fish (like Danios) is to painlessly destroy
the fish. Large fish, such as big cichlids and Koi, can sometimes be
treated by a vet, either through surgery or via drugs. Now, this isn't
to say that destroying the fish is the end of the story. Whenever fish
sicken or die within a short space of time, you need to wheel out the
nitrite and pH test kits. Use the nitrite test kit to make sure the
filter is working properly. If the nitrite level is anything other than
0, you have a problem. Likewise, the pH test kit will reveal if the
water chemistry is stable. For the collection of fish you have, the
ideal pH is around 7.5, and more specifically you want moderately hard
water as well. Also, you might consider increasing the water changes. A
good level is 50% weekly, though if the tank is understocked, you might
be okay with 25% weekly. Cheers, Neale>
Update-Zebra Danio with growth
PICTURES 9/23/07
These 2 pictures show the growth on the Danio- the first one you can see
how it protruded. The second one, only about an hour later, is of the
dead fish- it was stuck to the water intake on the growth side, and the
growth was no longer protruding and looked like the skin was rubbed off,
but you can see the size/position. (I do have bigger pictures, if
needed.)
<Definitely a tumour of some sort. No cure in a fish this size. Can be
caused by any number of different things. Concentrate on check water
quality and chemistry, and then acting accordingly. Cheers, Neale>
Update: Zebra Danio with growth
9/23/07
Hello,
<Hello,>
I sent a question earlier today regarding my zebra Danio with a growth
on its side-it had some details about the problem, and the history of my
tank (acquired as part of a business purchase.)
Unfortunately, the Danio has died. One moment it was schooling and I was
trying to take pictures, I came back and it was dead and stuck to the
water intake. I have taken several pictures which I am sending in a
separate e-mail, as I am still wondering what this was and what caused
it, and I am worried about my other fish as I seem to have more
problems.
<Ah well, nature took its course there...>
I wanted to give a bit more info as I was in a hurry earlier. After
e-mailing you, I did about a 20% water change-I replaced 9 gallons.
My standard procedure involves mixing the tap water with a dechlorinator
in a 3- gallon bucket, then adding slowly to the aquarium in case of
temp variations. I used Stress Coat by Aquarium Pharmaceuticals. I have
3 gallons marked on the bucket and added 3 ml of product to each bucket,
as directed on the product for stressed fish. (is this a suitable
product, btw? I noticed your article talking about "real" dechlorinators
but not sure how to tell which is which.)
<They're all "real", but the question is whether or not your
dechlorinator removes chloramine as well. Some do, some don't. If your
local water board puts chloramine into the water (not all of them do)
then adding a standard dechlorinator without chloramine remover results
in high levels of ammonia. This ammonia is toxic to the fish. 'Stress
Coat' has chloramine remover, so should be fine.>
I have a hang-on "Aqua Tech 20-40" filter, and also replaced the filter
cartridge (not the biological medium, just the carbon filter.)
<I'd bin the carbon, and add more biological filter media. Carbon is
redundant in most freshwater tanks, and is a positive risk in some ways,
because it removes medications.>
I added new water slowly to minimize any temp variations. I usually
match the new water temp to the existing water temp by the decidedly
low-tech method of "feeling."
<It doesn't really matter too much if the new water is cold. Provided
the water temperature difference is a few degrees C, the fish couldn't
care less, and some, like Danios and Corydoras, actually like swimming
into cold water.>
I noticed the water in the aquarium seemed awfully warm, but thought
that since the heater had turned on I must have been mistaken. I little
later, I noticed the heater still on. On a whim, I pulled out my candy
thermometer and found the aquarium water was between 85 and 90 degrees.
I unplugged the evidently malfunctioning heater, which was set to the
lowest heat level.
<This happens from time to time. One approach that works well is to use
two slightly too small heaters instead of one. For example, if your tank
needs a 100 W heater, use two 50 W heaters instead. This way, if one
sticks in the on position it cannot "boil" the fish because it is too
weak to heat the tank dangerously high. The other heater will switch off
normally. All this said, modern heaters from reputable manufacturers
tend to be very reliable.>
I know that the water I added was slightly cooler than the existing
aquarium water, so there is no telling how long this thing has not been
working right and I am wondering if the hotter water was the reason I
lost my swordtail.
<Possible, but unlikely. Generally extremes of temperature cause obvious
problems first: if too hot, the fish gasp at the surface, if too cold,
they become lethargic and off their food.>
I had noticed the heater seemed to be on a lot, but I was not really
sure how warm they needed the water to be and as the heater was
relatively new and was supposed to automatically regulate the temp, I
assumed all was well.
The fish were all acting fine, and were not gasping at the top or acting
distressed- the Corys happily scavenging and the Danios hanging out near
the top.
<Very good.>
About an hour later, I went to check again, and one of the Corys was
dead, just laying upside down on the bottom.
<Curious. At this stage, I'd be whipping out the nitrite test kit.>
Now I am wondering if I inadvertently caused the death by unplugging the
heater and causing a rapid temp drop, but I was afraid of how high the
temp would go. The candy thermometer says the temp is 85 now. I also
can't figure out if something went wrong at the water change, although I
used the same bucket and did everything as I always do.
<Water doesn't tend to rapidly cool down or warm up, and Corydoras in
particular have quite a high tolerance for extremes, at least in the
short term. They are air breathers, so able to tolerate warm water, and
the common species (peppered and bronze Corydoras) are subtropical fish
that can tolerate cold water for weeks at a time in the wild.>
Right now the heater is still off. The Danios seem agitated, although I
may just be nervous.
<Again, Danios are subtropical fish, and generally tolerant of cold
water for short periods. So lack of heat, unless the room is very cold,
shouldn't be an issue.>
I am out of water test kits- I tested frequently when I added the Cory
cats about 3 or 4 months ago to make sure of no spike, but haven't
tested recently As I inherited the tank after it had been established
for years, and have only added a couple fish, I have never had a reading
over 0 on ammonia or Nitrite, and Nitrates have always been under 10.
<That was then, this is now... do the water tests. Nitrite and pH are
essential here, as both are good indicators of background changes.>
I should mention I consider myself a complete newbie. Although I've had
this tank about a year I have not really added many fish, basically just
doing water changes and letting it be. I added the hang on filter, the
airstone, and the heater, it had none of the above. There was an
existing undergravel filter but I realized that it did not seem to be
properly set up- it was just a loose tube from an air pump pushed down
into the tall tube without being connected to anything, and I wasn't
sure how to fix it. (please excuse my technical terms.)
<Hmm... normally their is a transparent vertical tube a few cm in
diameter in one corner of the aquarium. This is connected to a filter
plate underneath the gravel. An airstone is placed at the bottom of the
vertical tube. As the bubbles rise, they pull water up the vertical
tube, and this up-flow of water draws water into the undergravel filter.
While considered "old fashioned" nowadays, a properly maintained
undergravel filter works very well. It is possible by disconnecting the
undergravel filter you've reduced filtration capacity below that needed
for your aquarium. Without an undergravel filter, you need an external
or internal filter that generates turnover of not less than 4 times the
volume of the tank. So if, for example, your aquarium holds 100 litres,
the filter should be rated at 400 litres per hour.>
I wanted to take the time to do more research before really getting into
adding fish, etc, as I didn't want to rush in and kill anything, and
have been too busy to do much with it. I have had the David Boruchowitz
Freshwater Aquariums book for a long time, well before I had this tank,
and had wanted a tank a long time but never took the plunge. The book is
great, and has lots of advice for getting started the right way, but not
really anything about what to do if you run into a problem.
<Ah, well, maybe WWM can help out here!>
Anyway, if you can, please let me know:
1. If the growth seems to be some sort of parasite I should worry about,
or something individual to the fish.
<Not a parasite.>
2. Is the death of my swordtails related to this recent death?
<Quite possibly; if conditions are "bad", fish may all die from
different diseases but were ultimately connected to the same cause.>
3. Was the high water temp likely the cause of all the problems?
<Possible, but unlikely. Unless the water went about 30 C, there
shouldn't be any immediate risk to your fish. That said, the ideal
temperature for your collection of fish is around 24 C, given you have a
mix of tropical and subtropical species.>
4. Do I need a new heater with the fish that I have?
<Well, you need a heater, yes.>
I live in the Houston, Texas area. It stays pretty hot, so the AC runs
almost year round. My house is pretty much a constant 77. I had been
keeping the top off the aquarium as a lot of sun comes in the windows
and I didn't want it to get too hot. I was reading the online article
about the sub-tropical aquarium, with no heater- would this be a good
choice for me?
<Depends on the fish. Even in subtropical climate zones, having a heater
set to its minimum setting is a good idea. During the summer here in
England, I turn the heaters down to 18 C. This way, the fish get the
nice, natural variation in temperature they prefer, but I get the peace
of mind of knowing if there's an unseasonably cold night, the fish will
be fine.>
Of course, I'm adding nothing until I've figured out what the problem is
now. I just have 2 Cory cats and 2 zebra Danios left, would they be OK
with that kind of setup?
<What kind of set-up? A subtropical one? You appear to have zebra Danios
(Danio rerio) and three-line Corys (Corydoras trilineatus). Both of
these will tolerate fairly cool water quite well, though only Danio
rerio is truly a subtropical fish. I'd recommend adding a heater but
setting it to slightly below normal, around 24 C. Most of the time the
heater will stay off, given where you live, but it'll come on during the
colder times of the year.>
I basically want something with fairly hardy fish, as my kids get pretty
attached to them. I'd like to add some more Cory cats- maybe a total
number of 6, and another 2 zebra Danios. Then I am assuming I can add
one more small school - what would be a good choice- I was looking at
perhaps 3 or 4 white clouds, although my young daughter would like
serpae tetras.
<Research your fish carefully. Corydoras and Danios work best when kept
in large groups of their own species. In the case of Corys, they school
nicely and become much mess shy and nervous. In the case of Danios, you
don't get so much fighting between the males. Serpae tetras should be
avoided if possible because they are notorious fin-nippers, and
Corydoras seem to be prime targets for nippy fish. White Clouds, on the
other hand, are good subtropical fish and would do well at 24 C. They do
tend to get bullied by the slightly larger and more boisterous Danios
though, so approach this combination with caution.>
As it is one of those annoying tall aquariums, and the Danios hang out
at the top and Corys hang out at the bottom, perhaps you could recommend
something that would like the middle ranges.
<To be honest, my first call would be to swap the tank for another if
you can. Choosing fish for a tall tank is throwing good money after bad:
tall tanks hold fewer fish than long ones (because of surface area at
the top for gaseous exchange) and schooling fish especially don't enjoy
the limited swimming space. You can obviously re-use the filter, heater,
etc in a new aquarium. But if this isn't an option, then perhaps your
best bet would be paradise fish (Macropodus spp.). While the males are
aggressive (so only get one, or none at all) the females are harmless
enough. They are classic subtropical fish, and when mature have
beautiful colours: blue and red stripes.>
Thanks for your assistance, I've been reading quite a while and enjoy
it.
Sarah
<Hope this helps, Neale> |
.jpg)
