Three dead overnight

I woke up this morning and checked on my axies as I do every morning, and found one of them laying on his side. I grabbed a net and poked him, and he was stiff. Checked the other two in the tank with him, and both of them were dead as well. Three 7" axolotls in a 20 gallon aquarium, bare bottom but with some fake plants and decorations to hide behind, and three potted aquarium plants. I've been keeping them like this since February (started out with a group of 5 and moved two others to another 20 gallon. Water changes haven't been quite as frequently as I like, but on the over-filtered tank, ammonia, nitrite and nitrate are always perfectly fine (0, 0, and under 15). Water is hard well water for them (I bypass the softener to fill their tank) with chlorine injected to the entire plumbing system (then removed with Prime). This is the same water I use for three tanks of African clawed frogs, and three aquariums of fish (except I don't bypass the softener for the fish). I've never had a problem with this tank, or with any of the axolotls. All three of these guys are growing well (in February they were less than 2" and at death were all at least 7") on a diet of less than 10% HBH Pellets and 90% worms (red wrigglers and canadian crawlers normally, and in the last month and a half or so I switched to red worms/European drift worms/panfish worms).

The change? A new pack of worms. I can't guarantee this was the problem, but it certainly sounds like it to me. Night before last I fed them some of a new packet of panfish worms from Wal-Mart that I've had in the fridge for about two weeks. Yesterday I didn't feed them (I only feed every 2-3 days), but all three were active & moving around. The last worms they've been eating were bought at the same time, but this was the first time I fed them worms out of this container. This morning, all three were dead- their bellies were bloated, and their throats looked ready to pop open.

The part that confuses me is that my other two in a different aquarium ate these exact same worms, and they're perfectly fine. For the moment at least.

Any thoughts on anything else it could have been that would suddenly kill all three?

I don't think it was the worms, especially if the other axies are still alive. Do you know if someone had happened to clean in the room they are housed in or even a nearby room with some kind of aerosol cleaner?

How awful for you. I hope you manage to solve the mystery.

Ouch, that's nasty.

I think we can all agree that the blame for this rests firmly upon Wall-Marts shoulders (that's ASDA for us Brits!)

Harry Thompson said:

I think we can all agree that the blame for this rests firmly upon Wall-Marts shoulders (that's ASDA for us Brits!)

Click to expand...

I wouldn't be so quick to jump to conclusions. I have used these same exact brand of worms for years from Wal-mart without ever an incident. The fact that the other 2 axies that are in a completely seperate tank seem to remain unaffected leads me to think it is because of some other cause. If it was the worms I would think it would have killed these other 2 axies just as quick as it did the other 3.

For three to all die at the same time there has to be something wrong with the water.
Something had to change to "shock them". Fumes from a household cleaner or maybe household pesticides can be absorbed by the water. Did you have a party were there was alot of people smoking? This can be absorbed also. Second hand smoke for you Axies. Was there a quick change in their water temp. Did you add a new piece if driftwood? Is there anything metal in the tank. It shoudl be removed. Was their death after or before a water change? You would be surprised how fast ammonia and ph levels can change. I would never go longer than 2 weeks before doing a 10% water change. I never do anymore tha 10% 3 times a week because of the stress that can be put on the animals. I also use air line tubing to add water so the water chemisty changes do not happen to quickly. So many things can go wrong with water quality.

No fumes of any sort- I have a bird in the same room, and the bird definitely would have died from fumes before the axolotls. Also, there are three aquariums in the same room (the other one with axolotls, and two with fish). We don't use any cleaners that could cause a problem, and nothing is ever used near the animals. There were no new additions to the tank, either. It's been at least 3 months since I added the last plant, and it's the most recent thing. And no temp fluctuations any more than normal. The ONLY thing different at all was that it was a new container of worms. And it does seem odd to me that the worms would have killed those axies and not the other, especially since those three were the biggest ones. I agree that for all three to have died at once, it had to have been something that changed; it could not have been an illness that went unnoticed, or anything like that. The thing that makes me think it was the worms is that they were so bloated, especially in their mouths & throats.

I really have no clue. The axolotls could have been dead for 10+ hours, so I didn't see any point in testing the water that they'd been sitting dead in.

Sudden deaths occur when an acute trauma happens. I would be suspicious of electric shocks (short circuits), and lethal, potent toxins.

The only thing electric anywhere near the tank is the filter, which is a Penguin 150 that has been running for 4 or so years now. I'll have to take a look at it, and see if something has broken in it.

Other than that, as I've said, the only toxins would have had to come from the worms. There's nothing that could spill in the tank, and we don't use anything in the room that would have harmed them; if anything had been harmful, it would have killed the bird first, and at the very least would have affected the three other aquariums.

Another note- the two remaining axolotls are doing perfectly fine tonight.

Thanks for the input, guys.