Dwarf Neon Rainbowfish acting strangely.

[Kris_H]

Small update to this, one of the Rainbows that had shown good signs of improvement has rapidly gone downhill. This morning he was eating flakes from the surface and acting normal as he has been doing for the past few days. Well, about an hour ago I noticed he started working his mouth and had really coloured up. He was darting around on the spot and swimming frantically. I was watching him for no more than five minutes when he swam to the bottom of the tank and keeled over onto his side. I quickly netted him out of the tank and setup a temporary aquarium out of a large container filled with fresh treated water but I do not have a great deal of hope any more. Water in the tank is still testing fine, did a very large water change not two days ago.

Looking at the fish, again no external signs anything is wrong at all, there have been no changes to the tank apart from the water change a couple of days back. This particular rainbow was one of the ones that was eating lots and showing signs of being well, but now this has happened. In the container that has a small submersible pump and a heater he is generally flopping about looking terrible. I'm going to put a very small amount of aquarium salt in there because honestly at this point I really doubt it will do any harm. I've read it will reduce stress so if nothing else at least it would have done that for him in what are probably his final hours.

(Small Edit to say that he wasn't displaying mating behaviours. I know that colouring up and swimming frantically could be misinterpreted as such, but this was completely different to that. He was holding his mouth open wide and darting around in a completely uncoordinated manner in a similar fashion to the first rainbow that died. I suspect that all of the Rainbowfish fish are going to succumb to the same fate sadly. One of them is still hanging at the surface and not eating just like they all originally were)

Edit2: The Rainbowfish has now died.

 

[Kris_H]

I'm very worried now. Just done a large water change because four of my six guppies are just hanging at the surface lifelessly. One of the Moscow Reds who used to be the most active fish is just parked in the roots of the floating plants. I don't know what to do . No marks on their bodies. Tested water with both of my kits before the change, Ammonia 0, Nitrite 0, Nitrate 5.

They're not gasping, just hanging at the surface of the water. I've turned the air pump on, but as there is plenty of surface agitation in this tank so I doubt it's an oxygen issue. The Tetras, Corys and Remaining Rainbows are still acting like they normally do.

 

[Byron]

This is certainly not an issue of wrong parameters with guppies that prefer harder over softer water. I did suggest previously that there may well bee some other issue. I don't like to advise on disease as my experience (fortunately) is so very limited. I am taking it that the guppy trouble was prior to this latest water change, not resulting from. It is possible the dwarf neon rainbows brought some internal problem with them, such as a pathogen or internal protozoan. I have twice had the latter, and aside from fish dying it is not something you can see externally. While i generally counsel against treating without knowing specifically what the issue is, this is a case where medicated food might help. Metronidazole added to the regular food for a period of 10 to 14 days might be advisable. Seachem make a product called MetroPlex which is metronidazole. It is a white powder, and is most effective taken internally with food rather than added to the water (the latter may often be useless). This is an antibiotic, and will not harm the fish listed here. The fact that some of the fish in the store came down with this would suggest an internal protozoan...have any more of their fish died?

Quarantining new fish for several weeks (five, six usually) in a separate aquarium is strongly recommended. I have been in this hobby for over 20 years, and never quarantined and aside from ich a couple times, never had issues. But times have changed, and twice in two years taught me the value of quarantining. Something like an invisible internal protozoan can wipe out half the tank of fish in a week or two before you know it.

 

[Essjay]

Kris, I notice that you spell colour with a u and use litres rather than gallons - are you in the UK? if you are you will find it virtually impossible to get metronidazole without a vet's prescription.

However, i have been told that Waterlife Octozin contains dimetronidazole which is supposed to work on protozoan infections.

 

[Kris_H]

Thanks for your help.

I've ordered the Seachem product however it will not be here until next week. Sadly one of the Guppies has gone, he was swimming around in the exact same manner as both of the Rainbows so I took him out and he passed away in a tub I have setup. My only hope is the MetroPlex saves the remaining fish that are still active and eating with the understanding the we are taking a bit of a shot in the dark here.

I too have been somewhat lucky and I suppose foolishly I'd never really quarantined fish. Just made sure not to put the store water into my tanks and had never had an issue. I've even managed to escape ich across 3 different tanks. I've been doing a little soul searching regarding my own fishkeeping practices. If I do continue on with the hobby I'm going to start keeping new fish in quarantine and give them a small methylene blue dip. I've just fitted a UV sterilizer to my filter which granted is nothing more than a token gesture at this stage, but if it even slightly reduces the spread of pathogens in the future then it will have been worth it. I've also purchased each tank their own separate maintenance equipment so as to not spread whatever this is around.

Anyway, if the remaining Rainbowfish are still alive when the MetroPlex arrives I'm going to feed them frozen blood worms soaked in the MetroPlex and garlic in the hope I can stimulate their appetite. Three other guppies are barely feeding, but they are still at least making some effort. The other two Guppies are still very active as are the Tetras and Corydoras.

 

[Kris_H]

Kris, I notice that you spell colour with a u and use litres rather than gallons - are you in the UK? if you are you will find it virtually impossible to get metronidazole without a vet's prescription.

However, i have been told that Waterlife Octozin contains dimetronidazole which is supposed to work on protozoan infections.

I am yes! I just purchased the SeaChem product Byron mentioned on eBay. The price was eye-wateringly high, likely because I'm not really supposed to be able to get hold of it from the sounds of it!

 

[Kris_H]

I now have both on the way, the Waterlife Octozin will be here on Monday. It's worth a shot I suppose, I have nothing to lose.

Thank you all again
Kris.

 

[Byron]

On the metronidazole, once you start, you must feed nothing else, meaning,m only food (which can be varied) that is mixed with the antibiotic. And, it takes a few days before it will start to work. If this is an internal protozoan, fish will likely be dying all along. Again, there is no certainty this is the issue. Guppies are not "strong" fish any longer, with the decades of inbreeding they have been severely weakened.

If you do not open the metro when you receive it (if by then you either don't have the problem, or the other drug works) it will keep for some time in a cool dry place.

 

[Kris_H]

Thanks again. I'll try the Waterlife Octozin first because it will arrive a few days ahead of the MetroPlex. I'll take carbon out of the filter and maybe switch the UV unit off - not sure if that's required, I'll look into it.

From what I have read, the Octozin is placed into the water column so I'm assuming I do not need to worry about soaking it into their fish foods. For the MetroPlex using it with freeze dried foods will be ideal because of the absorbent nature of them. I'll try with Frozen Blood worm first because it may be the only way I can coax the Rainbows into eating.

 

[Kris_H]

About to lose another Guppy and Rainbow. The Rainbow was swimming erratically like all of the others were and the Guppy was head first on the substrate barely responsive. Moved them to the tub. This is unbelievably brutal

I'm scared that what ever this is will travel to my other tanks. I'm sure the only thing that has been used between the different aquariums is the pump, pipe and bucket I use to refill for a water change. I have clips on the tank brace for the affected tank that holds the refill pipe above the water so with a bit of luck nothing has transferred across from that. It is also drained via a dedicated drain I plumbed in, I just disconnect the filter intake and pop the pipe in there and gravity does the rest.

 

[Kris_H]

If anyone out there in the future has the same issue, I'm posting an update to this with what happened and what I tried to do to correct this:

To recap the symptoms with the original Rainbowfish I introduced were: hanging around at the surface of the water refusing to eat. They'd clearly be interested in the food, you could see them looking but they'd nose away from any pellets or flakes. After about a week, three of the Rainbowfish started to act normally. They'd happily accept both pellet and flake foods with quite the appetite. The also behaved exactly as I've read Dwarf Neon Rainbowfish should. (Aquarium is 2-3 years established with no ammonia, nitrite and low nitrate tested)

As the parasite/disease progressed, the Rainbowfish started to succumb one by one. The onset of death was surprisingly fast with the exact same symptoms in each fish. The 'healthiest' fish would be the first to die, this is something I noticed when it spread to other fish also. One minute the fish would be swimming around as normal, the next they'd start to looked panicked, they'd then swim uncontrollably both upside down and into objects followed by death. The onset of death from noticing these symptoms would be approximately 20 minutes.

In total the death toll was 17 fish. The first to start dying off were the Dwarf Neon Rainbowfish, it then spread to the Guppies and possibly the Otocinclus (the Otocinclus may have been killed by the medications in the tank, more on that later). The Cardinal Tetras, Glowlight Tetras and Albino Corys do not seem to have been effected.

The following Medications had no effect:
Praziquantel
Aquarium Salt*
Seachem Paraguard*
Methylene Blue.*
*These were dosed in a separate tank

I'm unsure if the following had any effect on fish that now remain, there were a few losses after using both though
Waterlife Octozin (shortly after this was dosed into the aquarium, all six of my Otocinclus died)
Seachem Metroplex (The last Guppy to die had been eating food medicated with Metroplex in his final two days, admittedly it could have been too late for him if this did have any effect.)

Fish in my other aquariums are unharmed. Worth mentioning because they are maintained on the same water change schedule, water source and foods. At the first sign of trouble with the affected tank, I made sure nothing was shared between the different tanks.

There have been no deaths the past day although I have no real idea if this is over due to the symptoms I've observed. I've switched the UV unit back and will continue feeding food medicated with Metroplex until the three week course is up.

I'll post updates if I lose more fish to this, if I forget to post any further updates assume that no more fish died!

Original Stocking:
5x Dwarf Neon Rainbowfish
6x Otocinclus
6x Guppy
6x Cardinal Tetra
5x Glowlight Tetra
6x Albino Cory

Remaining:
6x Cardinal Tetra
5x Glowlight Tetra
6x Albino Cory

Apologies for not updating sooner but my Internet is currently down.

 

[Byron]

Thanks for posting this summation. From this I would suggest that the newly acquired fish introduced an internal protozoan that spread. Without knowing what it was exactly (post-mortem analysis by a microbiologist would be necessary) there are few reliable options, but metronidazole seems to be one that is frequently recommended and usually successful. However, it takes several days once it starts getting inside the fish to become effective, just like antibiotics with humans. And like the latter, it has to be continued for the full course. Fish already affected past a certain point, as opposed to being merely exposed initially, will die over the first days of treatment, as here.

The rapid death of otos after certain medications added to the water illustrates the danger in using any medication in the water or when the actual issue can only be guessed at. But of course, we cannot say that the otos had already contracted whatever this was. Some of the mentioned initial treatments would have serious debilitating effect on certain fish in particular, including otos, but you used them in quarantine--though this would have had no effect on the protozoan in the main tank.

The UV cannot hurt; it obviously will only be effective on organisms in the water, and only if the water all passes through the unit, which of course is impossible as the tank does not have flow-through water so no contaminated or untreated water has the chance of mixing at all with the UV treated water.

 

[Kris_H]

As another week has passed I thought it would be good to update once more: No more fish have died!!!

Cannot say for certain which of the two (Octozin or MetroPlex) had the most effect however one of those two or both seems to have put the brakes on losing more fish.

A couple more notes that are worth mentioning about the treatments:

With the Octozin in the water, the Albino Corys weren't acting normally, I noticed they had become sensitive to light. In the room which the tank housed; the ambient lighting in the room slowly ramps up to full brightness before the hood lights switch on, similarly when the tank light goes off, the ambient room lighting drops off over the course of 45 minutes. Now, before any of this happened the fish were never visibly freaked out by the tank lights turning on or off. With the Octozin present in the tank water, the Albino Corys would really freak out whenever the hood lights switched on/off. This behavior was observed until the large water change was carried out that removed the Octozin. Remember also that the Otos were quickly wiped out when the Octozin was added so please be very careful using this product with fish that are sensitive.

Another change I noticed was that one of the Cardinal Tetras had started to bloat up when the protozoan was actively killing fish. After I used the Octozin, the cardinal quickly returned to their ordinary size. I had forgot to mention this in my previous postings here but thought it was worth noting.

Anyway, a big thank you to everyone who helped on here! I cannot express how grateful I am that we at least managed to save 17 of the fish. The take home from this for me at lease is to quarantine fish if you have the capability. I've now setup a dedicated tank just for this purpose so that any future fish purchases have a far lesser chance of wiping out what is already there. I already have fish in there waiting to inhabit the tank where the others sadly perished.

Thank you.