My Zebra Danio Are Slowly Dropping!

[scouse_andy]

I have a Juwel Rio 240 litre tank and it has been set up for about six months now.

I did a fishless cycle before adding any fish and everything in the tank seems stable, I have been testing the water weekly and ammonia and nitrite are at zero and nitrates negligible as i had loads of fast growing stem plants (these have gone recently but I do a 15% weekly water change to keep nitrates down.

Fish have all been happily getting along and I went away on holiday for a couple of times in August, for a week at a time, I left the fish without food for this time. After the first holiday all was fine, I was back for a week and fish were well, stats were normal. After the second holiday the stats were still normal but I noticed a few of my Zebra danio floating motionlessly on the top then their tails would curl down they'd float down to midlevel, speed around the tank for a minute and then stop again and drift. This has been going on now for about a month. I have lost 3 danios out of a big shoal of 22 I had (6 adults and 16 babies who are about 5 months old and almost as big as their parents now). The fish still present the same symptoms, floating at the top with bent tail for a bit then being normal then floating again! Everything else in the tank appears normal and I have had no other deaths. I have 2 bristlenose plecs, 3 siamese algae eaters, 7 black phantom tetras and 5 swordtails in there currently. I'm not fully stocked yet but am awaiting some diagnosis on the danio before I even think about carrying on stocking.

It just strikes me as weird that it is only the danio effected, when they are widely considered to be one of the more hardy species of fish.

The only contributory factors that I can come up with are as follows:

1. poor oxygenation of the water, just the juwel powerhead in there so I've added an airstone but no noticeable difference

2. I read on here that in hard water areas where heavy metals will have been removed, you can mix hot and cold water from the tap then dechlorinate and add to tank. I started doing this a few weeks ago but have now stopped. Could this have caused a problem?

3. as a multi-tank-syndrome sufferer, I bought a couple of second hand tanks off ebay. One came with some flake food which was opened. I have been using it for the last few weeks but have since thrown it out, I have used this same flake in all my other tanks with no adverse consequences.

It really is a mystery to me, I read quite widely on here but can't find the cause so I'd really appreciate some help and suggestions to help me sort this problem.

thanks, Andy.

 

[WILDER]

I mix hot and cold water and never had any problems, I use a declorinator that removes heavy metals.
Darting poor water qaulity, parasites, toxins, to stray voltage.
Any bent spines or curving of the spine.

 

[Tokis-Phoenix]

If they are hanging around the at the waters surface a great deal, only to dart around the tank for a little bit and then return to hanging around the surface, they could have gill flukes (this sort of behavior are some of the main symptoms of gill flukes).
A great deal of fish carry gill flukes, they are invisible to the naked eye, and usually the fish can handle the gill flukes for a long time with no visible health problems, but when conditions change with stress the fish out, the gill flukes take advantage of the fishes stressed out vunerable state and over-power the fishes imune system.

I would advise watching the danio's in the tank for about 30mins to see if any of the danios are displaying flicking and rubbing symptoms (when the fish "itches" or scratches itself by darting against against objects/stuff in the tank like the substrate and decor), if they are displaying these symptoms i would definately put my money on the danio's having gill flukes .

 

[scouse_andy]

The back of some of the fish droops down as in the picture there but when they swim it levels off, they do have clamped fins quite a bit too though, it seems to come and go from still and droopy to darting with clamped fins to normal swimming.

I have spent a good while looking and haven't observed any flicking or rubbing. Thanks for the suggestions both of you.

 

[WILDER]

Not to panic you but see alot of danio with fish tb.
Gill flukes signs are.
Pale gills with excess mucas on them, to red and inflamed.
Gasping at surface of the tank, laboured breathing.
Flicking and rubbing.
Spitting food out.
Can go thin.
Swim in a jerky movement.
Being lethagic.

 

[scouse_andy]

I had considered TB but thought it was pretty rare and worst case scenario. I've had the adults in this tank for about 6 months and symptoms have only just shown up recently. Would this be the case with TB?


No jerkiness when swimming, or mucas or red on gills.

No gasping or laboured breathing although they do float on the top. Some are seemingly completely unaffected whereas the others stop and start, presenting symptoms then shoaling normally.

They never spit food out, greedy little fellas but I would say that very lethargic is a good description. Before I lost my third danio earlier this week I did notice that he was looking rather skinny although the danio currently demonstrating odd behaviour do not appear skinny.

 

[WILDER]

Being skinny can point to fish tb to internal parasites.
Check the anus of the fish to see if its enlarged or red and inflamed.
What does it look like when they go to the toilet, seen any red worms prutruding from the anus.

 

[WILDER]

With the fish being skinny and bending at the tail I think I would get this wormer.
If it is tb I would research it, but I would try the wormer first.
Good luck.
http/www.aquaessentials.co.uk/index.php?...roducts_id=1327

 

[scouse_andy]

I will be getting some Flubenol later this week. I've spent a while observing the fish in the tank this evening and noticed some white stringy cotton-like poo on a few of them. Here are a couple of pics. I wouldn't say they look inflamed in the anus but certainly stringy cotton poo doesn't look good.

They do seem to be spitting out the food before re-eating it but not sure if this is a symptom of an illness or something fish do to break down bigger flakes into smaller pieces.

I should also mention that I took possession of some free fish from a fellow board member about 4 months ago. She had some fish from the same tank who subsequently (a few days later) developed inflamed anuses and it was diagnosed on here as internal parasites. She treated with flubenol, all survived and there are no further problems in her tank as far as I am aware. Could these parasites have lived undetected in my fish for 3-4 months and now surfaced? Perhaps 2 one week holidays recently has stressed the fish and the parasite problem has now manifested itself.

Just a theory but any thoughts?

Looking at the photos does it make a diagnosis easier and, if so is Flubenol still the best way forward?

Many thanks, Andy.

 

[scouse_andy]

Here is a link to the thread of the lady who had internal parasites. I got some fish off her about 4-5 days before it all started in her tank. Is it likely that similar things are afoot in my tank?

parasites

 

[WILDER]

The symtoms are showing up now as internal parasites.
White stringy poo.
Inflamed anus.
Going skinny.
The fish can bend with internal parasites.
Spitting out food is a sign of parasites like flukes.
Flubenol is a great med used it myself on internal parasites I had a skinny guppy and dosed the whole tank.
Sadly that guppy didn't surivive as once they are infested with them even the med can be to late as the parasite does alot of damage.
fish can get internal flukes as well like liver flukies.
I would get the med as fast as possible, you might need to dose anti internal bacteria med also, as internal parasites cause bacteria infections.

 

[scouse_andy]

I have got the Flubenol coming in the post from Aqua Essentials.

Which anti internal bacteria med would you recommend and will it harm the filter?

Cheers, Andy.

 

[WILDER]

This bacterial med dosn't harm the filter, anti internal bacteria by interpet.
Good luck.

 

[scouse_andy]

I've had a good look at my danio this evening and one looks particularly ill with very red sore gills. Looks like gill flukes then I guess, along with the internal parasites, the flubenol should hopefully arrive tomorrow so I will dose the tank as soon as it does.

I will be getting some interpet number nine anti internal parasite too. Am I alright to dose these two meds at the same time or do I have to dose the course of flubenol and then follow it up with the anti internal parasites med?

 

[WILDER]

Yes you can use another med with flubenol it says so in the instructions.
Good luck.