Anyone ever had a fish die of old age?

[Toby_H]

Dying of "old age" really isn't a thing.
We labeled humans as such 100 years ago all the time simply because we didn't have the science to understand cancer, organ failure, etc, etc. As science evolved, death by "old age" started to go away and we began properly identifying those deaths.
Same thing is going on with our fish. Sure, common perspective may be Species X lives 10 years and a hobbyist may keep one alive 12 years. It's comforting to us to say they died of "old age" but in all reality they died of something.
Now we have to ask ourselves... Did living their life in a glass box put pressures on their health that compromised them to some degree? I don't think we can honestly deny that.

On the other hand... in most cases we are removing predatory threat, removing risk of starvation and many other common threats encountered in nature. So I'm not criticizing the compromises that come from aquarium living, but I'm also not denying them.

 

[Poseidon2.0]

The first Oscar I had as a kid in the late 70s lived for ten years in a tiny tank. I had him in a 30 gallon as I didn’t know any better at the time. I always imagine he would have lived much longer with the lather tanks I now have. I’ve since had Oscar’s live about as long in better conditions. The amount of chemicals fish are subjected to (like Safe) makes it difficult to make it to a natural end.

Our koi we kept in an outdoor pond for about 20 years before we had to give them up. I imagine they would have kept going for another decade or so. They were massive.

Currently as I am down to two tanks my oldest surviving fish are my black neons that I bred myself and are around 5 years old. They are stated to live only 3-5 years but mine seem to be going strong in their 24 gallon setup.

 

[neutrino]

Dying of "old age" really isn't a thing.

This is just semantics. The alternative would be to say fish have an unlimited lifespan-- unless something goes wrong or we do something wrong. Except they don't. Substitute "natural causes" if you like, or say organs and systems-- including the immune system-- age, decline, gradually cease functioning properly, or eventually shut down. It's all the same thing. Or, to paraphrase Gordon Lightfoot, they 'pass away to their natural decay.'

 

[neutrino]

Or, if you prefer, and as some academics define it, you can call it an emergent phenomenon occurring progressively in each and every individual surviving beyond a certain duration of life.

Whatever you call it, fish have limited lifespans, because it's a 'thing.'

 

[amazontank]

I had a male breeder l397 pleco die of old age. My guy just stopped eating color faded & a few days later passed away he was over 15 years old!

I wanted to add that the last few months of his life after he stopped breeding he lived with hundreds of fry & egg incubators.
The water was always prestine. Definitely old age on my guy.