What is lurking in my tank????

[J rider]

Hi everyone,

I am back after having healthy fish for about 2 months I have a sick one again. My last clown loach has been getting skinnier for about one week and his eyes are slightly cloudy. He is still eating and looks happy and active.

Symptoms:
I set up my 55 gal tank in September and have had 10 out of 18 fish die since then. First it was my zebra danios who got reddish gills then got skinny, lost their appetite and were removed from tank. They also hung at top and seemed luthargic. Some of them got a sort curved body structure.
Then 3 out of 4 clown loaches died. They also got slightly reddish gills. Their lateral line stuck out when they got skinny. They seemed to lose the ability to eat. Occassionally they would eat and spit the food out.

My 2 siamese algae eaters and 6 ottos have been unaffected and do not show any signs of illness.

Attempt to cure:
In January when the 3 clown loaches were sick I treated with anti parasite tabs with no success. I'm not sure if this rules out gill flukes b/c the fish were quite ill before I treated.

Parameters:
My pH has been stable at 7.6. My ammonia levels always zero. GH=8, KH=12.

Possible problems:
I am attempting my first planted tank so my nutrient levels have been unstable causing my plants to stop growing at various times. This may have led to unstable O2 levels. Since there should be no surface aggitation in a planted tank there was no inlfux of O2 from the atmosphere.
My temperature plummeted 3 times, due to my apartment temperature going down to 40 degrees!
I also was not so great with water changes. I think 3 times since September I changed the water after 2 weeks instead of 1. I usually do about 50% water change.
I feed every other day a rotation of blood worms, flake food, and mosquito larvae.

Set up:
55 gallon
304 Fluval
130 W 6700K

The reason why I really need your help is b/c I have just cleared my tank of plants (b/c they were dying) and if I think that drastic measures are necessary I may might to tear my tank down now and before I get a tank full of new plants and try again.

Questions:
Why have my 8 algae eaters remained so heathly through this whole ordeal?
What is lurking in my tank?

Thanks,
Jackie

[ChileRelleno]

I think you may have one or more parasites, internal and external acting together to wipe out your population.
I'm going to throw a list of possibilities at you and mark (*) my most suspect nasties.
Furunculasis
Pseudomone
Salmonidics
Argulus
Anchor worm
*Internal worms, various types.
*Gill flukes
*Avitaminasis
*Dactylogyrus
*Gyrodactylus
*Chemical stress, e.g. NH3 poisoning... etc...

[ChileRelleno]

http://www.aquavet.i12.com/Fish.htm
http://www.aquatronicsonline.com/hobbyist/hobbyist3.htm

[TankGirl]

I am leaning towards TB, or mycobacterium, especially with the symptoms of skinniness and lack of appetite, and the curved spine, plus recurrence. AFAIK there is no cure, and it is very contagious. Do a google on FW tuberculosis (mycobacterium) and if you think it matches up to what has been happening in your tank, then you will need to euthanize any fish showing signs, and completely tear down the tank and sterilize everything, unfortunately.

If you have no luck with parasitic meds then I'd consider this as the cause.

[ChileRelleno]

mycobacteriosis (Fish TB) commonly due to M.marinum, M.fortuitum or Nocardia, can present with a wide variety of signs such as chronic weight loss, exophthalmia, skin lesions and spinal deformities. Fish with gill hyperplasia, such as seen with chronic ammonia exposure may subsequently suffer secondary bacterial or fungal infections.The gill filaments are often so inflamed and swollen that the operculi are unable to close. The respiratory rate will be high.

Thank you TankGirl,
I missed that as its symptoms are quite lacking in the disease diagnosis chart I use primarily(Aquatronics) but it was pretty symptomatically accurate in the other.

[TankGirl]

It definitely could be parasites, and I sure hope so, since those can be treated with meds and raised temps.

That's why the symptom complex (taking into consideration the prior deaths and how they died) needs to be carefully evaluated before the dreaded tank tear-down occurs. I hate that!

[ChileRelleno]

J rider,
Check this out, any matches here, symptoms do seem to match your fishes? http://www.fishpalace.org/Disease.html#TB

[dr_girlfriend]

I dunno, I'm thinking possibly gill flukes....were the gills swollen on your afflicted fish? Or bacterial gill disease.
Did your fish get curve backs after you treated them with anti-parasitic meds? Sounds alot like flukes. Irritated gills, spitting food out....

[J rider]

Hi guys,
Thanks for the replies.

I was hoping more people would use the poll. Anyway, I had only 2 zebra danios who ended up with curved body and it was only when they looked really sick.

I treated with anti-parasite wafers when the clown loaches got sick. I did a triple dose and treated for a long time. They just got sicker and died.

Most pronounced feature would be skinniness.

Yes the gills did seem swollen at least for all of the zebra danios.

Another point to consider. In order to remove all the algae, I have been doing a water change (50%) every 3 days. The fish look so happy!

My last zebra danio showed signs of illness about 3 weeks ago and has since lost the redness in his gills and put on some pounds.
My last clown loach still looks thin but eats well and is very active.

Would anything recover like this if it was fish TB? Would water changes make less of the disease in order to temporarily let them live?
Lets keep thinking, please.
If we come to a consensus I'll treat the tank this week. But, I don't