What have you kept longest?

We have spoken about the oldest fish we have kept, but never about the species themselves? What's the longest you have maintained a species at one time? Was it always in the same tank?

The longest species I have kept is the Rummynose tetra along with the Celestial pear Danio.
I've had these fishes for a long time now, it's been more than two years. (Since my first "big tank").
They followed me through my multiple moves, and are now in a big 77 gallon tank

I've kept Rummynose Tetras the longest just like |_|_|. However, I haven't bred them or kept the same ones for my entire time spent as an aquariast. There's something about them that I really like....

I have a fish I love, a killie called A. zygaima. They live about 3 years maximum, and are fairly rare fish. When I got them, they were really hard to breed, and I made it a personal project to succeed with them. With the exception of a few months when I had only females and had a friend save me with males from my original line, I have had them breeding and replacing themselves since late 1992 or early 93.
They never stopped being interesting, and never became easy to breed. They've been in many different tanks, and in three different houses.
I have a friend who has a killie he fell for back in the 1970s. He figured if he didn't breed them, he'd never see them again, and he's still enjoying their descendants. That's the longest I know of.
Really, the trick is to stay in the hobby, and eventually you discover there's a fish you've had forever. No one plans to do these things. We just take a liking to a fish, and the next thing you know...

I've had Orange tailed goodeids for close to 15 years and Ameca Splendens for about a year less. Don't remember exactly which year I got them. The orange tails aren't as numerous (40ish) or as many extra large ones as there use to be, but that's probably because they are in my just stay alive tank. Meaning you get fed and water changed when I remember you are there but I don't spend anytime observing the going-ons. The Amecas are mostly in the tank in my son's room (the second least observed tank), although there are groups of 3-4 in several other tanks. The sons tank is about a 40 gallon and way beyond over populated I'm ashamed to say. They just keep reproducing and I really don't know what to do with the extras. I used to give them to a local store but they have had a tank full for years now, along with a tank of Orange tails I gave them over a year ago. They haven't reproduced much over the winter but with spring around the corner if a quarter of the large females drop I'm in deep trouble. I'd post a pic of how crowded the tank already is but I'm afraid I'd get unpleasant mail from fish enthusiasts.

One of the reasons I farmed out most of my uncommon wild livebearers and went back to killiekeeping was what Sailfinja describes - that tendency to get overwhelmed by numbers and to be unable to rehome fish. They breed til no one wants them anymore. Then the high numbers cause a crash, and it's lights out - the party's over.
With killies, they will breed like livebearers, but at a few fry per month. If you want the big numbers, you have to do things to make that happen. It lets you plan, space and timewise.

I have the perfect livebearer though, my ginger ale livebearers - Priapichthys nigroventralis. Every 28 days, like clockwork, each 1 to 1.5 cm female drops one or two fry. They live about a year and produce fewer than 15 fry in a lifetime. They have still managed to fill two tanks, but I know a wholesaler who takes all my surplus as they are much sought after in Europe and Japan. That, finally, is a manageable livebearer.

To the point, I think if you are going to keep a species for a long time, it helps if you can breed it to make it self-sustaining as a project.

I got my first Oscar in the late 1960's. 68-69? I have never been without at least 1, and currently have 5.Call it 46-47 yrs of Oscars, and pretty well the same amount for plecos, although there have been short interruptions of pleco owning.

We have had our black skirt tetras for a little over four years now - they were our first finned babies We originally started with 15 and we have lost two over the last year or so. Our 13 remaining babies are swimming strong and we adore them!

I am a relatively new Fish person as I am in about my 5 year or so and have always had at least 1 Betta and longest lived is my pleco. Currently still have some Bettas from my last spawns and have about 40 about 20 I want to re-home.