HELP Lesser Siren problems!

[CatmanJuice]

I recently (about 3 weeks ago) added a lesser siren siren intermedia into one of my fish systems. In about the past two weeks I've lost an alarming number of fish (realtively speaking) including a redtail cat, a tiger shovlenose (both I've had for approx 1 year), a polyepterus, and a few pl*ecos. Some of the cichlids in that system are now showing some problems with ich. I have had this particular system running for about two years, it is over 500 gal. of total water volume. I've tested my water and showing the following:
Temp: 78 F
pH: 6.8-7.0
NH3: 0.0ppm
NO3: 0.0-0.5ppm

Any ideas or advice would be great. I'm at a loss for ideas, I've read that Sirens have some sort of very protective slime coat, and other than that nothing. All fish are eating and behaving normally, even the cichlids that have some ich.
Thanks,

[tbone87]

This is just an idea:

I have read somewhere on the net that fish which have had disease or parasites, may have been treated before. As such, they are immune to the bad things, although these virus or disease still exists qithin them.

It could be ur siren has suffered ich before, still is carrying it, only that it is now immune and is passing it on to ur other fish.

I might be wrong, this is just my opinion.

[MatsP]

Generally speaking, Ich outbreaks are caused by some sort of stress-factor.

And whilst I agree with TBone that some pathogens can be carried by animals that have been "treated" to cure these, I don't believe that Ich is one of those - it is however a bit like common cold in humans: most of us carry a few cold-virus variants in our body at any time. Under normal circumstances, our immune system is capable of dealing with it. But if we get stressed (e.g. extremely tired, cold, hot, etc), the immune system doesn't cope and we become ill. Same applies to ich and fish - it's very possible that one of your fish was carrying ich when you added more livestock. The stress of the addition of your salamander may have pushed your fish over the "limit" that it can cope with.

It's not particularly important whether the new addition or the existing fish were the carriers of ich - the outbreak is still caused by the extra stress caused by the addition [or some side-effect thereof].

It also may be that you had a spike of ammonia (NH3/4) or nitrite (NO2).

Is your NO3 measurement really of NO3, and not NO2? In which case, your nitrate is REALLY very low - you must be doing very large water changes ever week. If it's the NO2 level, then you need to determine if it's 0 or 0.5 - anything above "measurable" is bad here. If you haven't done a measurement of N02, then you should do so, as it is one of the stressful toxins produced as a byproduct of the fish waste.

I would recommend treating with Ich medication - if you still have some catfish, make sure it's suitable for "scaleless fish" and make sure you follow the dosing instructions for scaleless fish (often "half dose"). I beleive Rid-Ich is one of the suitable products in the US.

Edit: I would also advice that I have NO IDEA how sensitive to medications your salamander is, so make sure that the medication is "safe" with those - I have no idea even where you would look that up.

--
Mats

[CatmanJuice]

Thanks for some thoughts guys.

Some answers: yes, my NO3 is 0.0-0.5 ppm. I do approx 30-50% changes every week. I am a firm believer that most of the fish I keep naturally live in a constantly changing environment in the wild (weather that is in a large river system or lake; new water is a constant) and believe that I should replicate it as closely as possible in captivity.

Secondly, I would never disagree with the stressful situation being a main cause of ich break-outs in a "normal fish tank" environment, but my "system" as I should have emphasized more is not a "normal tank". I have multiple tanks all on the same system water: I have (2) 40gal breeders, and (5) smaller approx 10gal tanks that all drain into a larger(approx 400gal) "pond" that also functions as a sump. The salamander was added into the pond part of my system, but fish in other tanks are now having problems too. So I do not believe the salamander is "stressing" the cichlids or cats out and causing problems in such a direct way.

Now, I do believe that we might be on the right track with the idea that the salamander might have brought in some sort of pathogen... I'm wondering now if it is something that my south american and asian fish have no sort of immunity to, due to not being exposed in a natural setting and thus never developing a defense to the pathogen.

Any thoughts???
Thanks again

[CatmanJuice]

OK, well Mats you are right my nitrates aren't that low. I just re-tested my NO3 using a new API test kit as well as the one at the LFS at which I work. Nitrates are still low, but I'd say they are still around 10.0-20.0 ppm according to both the new kit and the one at my LFS (throwing out old kit which did show 0.0ppm NO3 for ANY water I tested). Now I've also tested the NO2 and that reads out at 0.0ppm (nothing measurable).

SO the tests say:
pH-6.8
NH3- 0.0ppm
NO2- 0.0ppm
NO3- 10.0-20.0ppm

I did pick up some new therm. to make sure my temp is good.

[sidguppy]

best put the Sire in another tank.

first off: temperature.
25'C (thank you, Jools, for that lil nifty calculator ) is good for your South American catfishes and African Polypterus; but it's far too high for the Siren salamander.

yes, it can handle temperatures like that, but only for a shorttime, a month, maybe 2-3, after that it'll start to 'burn up'.
this is an animal from a temperate climate, not a tropical.
there are all kinds of issues; stress, oxygen, pollution etc.

it's much better to keep it at 15-20'C (59-68F) wich will be far too low for your fish.
in winter it should be cooled down to even lower temperatures.

it's also recommended that it's kept in a densely planted tank or with some piles of branched bogwood and pond moss or something; these love to crawl through vegetative matter.

if not only the temperature is not good, but they lack adequate hiding places; they'll get stressed.

stress in amphibia leads to more secretions from their skin. mucus, loads of it. and other things.
almost all amphibians are toxic, most to a low degree, some to a high one.
the siren isn't known as a venomenous animal; but be assured that it can and does excrete some kind of slime with a whole list of substances in it that will stress out your tropical fish......

even if it's just slime; it will not be good for the gills of your fish.

stressed fish develop ich!
oh, btw: meds for ich will kill your salamander in short order......