Nigel - 3 months old
Two and a half years later, Nigel is still with us. He spends his days swimming merrily about in the tank, coming up with new and exciting ways to tear up the aquarium greenery while I'm at work. He's also responsive and interesting to watch in ways I admit I didn't anticipate seeing in a goldfish -- he always swims to the top of the tank as soon as I enter the kitchen in the morning, anticipating food, and when I've got my hand in the tank fixing the plants he's managed to uproot, he comes up and whacks me with his tail!
Anyway, the reason I've introduced Nigel here is not just because he's a really cool fish, but because he's a living example of (a) how seemingly "simple" factors can greatly affect longevity, and (b) how it is very easy for these factors to remain unknown until luck or circumstances bring them to light.
Nigel, 2.5 years old
Right on the first day I got Nigel, I told myself, "I am going to keep this fish alive as long as I possibly can". However, I almost lost him within the first 24 hours.
My parents had kept small tropical fish before that apparently do reasonably well in smallish tanks, and they didn't know a whole lot about goldfish either, so they'd gotten me a small tank for Nigel -- its capacity couldn't have been more than about a half gallon. When I first put Nigel into than tank, he'd seemed more or less happy, but by the next morning, I found him sitting practically motionless at the bottom! Even more frightening, his fins were turning black. Needless to say, a trip to the pet store for supplies (and hopefully some good advice) was definitely in order.
At the pet store, I explained the situation as best I could to the resident aquatic expert. My suspicions were confirmed: Nigel was indeed dying in the small tank. The motionlessness was due to lack of adequate oxygen, and the fin-blackening was due to ammonia buildup in the water (as goldfish excrete a lot of ammonia). In order to save Nigel, I needed to get him into a bigger tank as soon as possible.
I came home from the store that night with a 5 gallon tank, filter cartridges, a transfer net, two plants, and a nice big bag of gravel. That tank (and the 12 gallon I eventually replaced it with) had a filter pump as well, which would help circulate the water, removing waste and debris and helping oxygenate the water. I put Nigel into the 5 gallon tank a bit sooner than the instructions called for (you're supposed to let the aquarium "settle" first so that you're less likely to shock the fish), which was something of a risk, but at that point I knew he'd definitely die if I left him in the tiny tank any longer. Happily, he perked up immediately once in the larger tank, and within about a week, all the black had disappeared from his fins.
Relieved at Nigel's recovery, I went to the Internet to look up information on maximum goldfish lifespans. I recalled some friends of the family when I was growing up having two very large, very pale goldfish that were supposedly around 20 years old, but I'd presumed that to be an anomaly and possibly a record-breaking one. However, what I found was nothing less than shocking -- not only did goldfish commonly live 20 or more years when cared for correctly, but that some members of the carp family (e.g. koi) could live to be over two hundred years!
There's no way to tell, of course, how long Nigel will ultimately live -- but it's certainly going to be a lot longer than if I'd not had ready access to accurate information about goldfish physiology and care. Fish are also a lot more interesting than many people give them credit for, and in fact, some fish (which I wrote about in my article A Menagerie of Longevity a while back) could very well be the ultimate longevity champions of the animal kingdom. This is wonderful for them, but unfortunately doesn't tell us much about what interventions might pave the way for similar levels of longevity in warm-blooded primates such as ourselves. However, the situation still makes an interesting analogy.
The point Nigel's brush with death (and subsequent robust health following improvements to his tank setup) brought home for me was that animals and their surrounding environments are systems. In many respects, Nigel, the water in the tank, the aquarium plants, the filter, and the "bio-wheel" (a rotating filter element populated with "friendly" bacteria) can be viewed as a kind of super-organism.
Humans are also "super-organisms" in this sense, scaling from our internal environment which contains numerous symbiotic microorganisms (along with mechanical devices such as muscles and valves), up through our external environment which contains the air we breathe, the foods we eat, the water we drink, etc. And like goldfish and all other animals, we are limited and vulnerable in various ways on account of the very same mechanisms that allow us to live in the first place.
Our metabolic processes permit us to take in needed energy to support our bodies over time, and yet, these processes create byproducts (such as Advanced Glycation End products) that contribute toward unpleasant, serious, and even fatal disease later in life.
Our immune systems "police" our bodies to prevent destructive invaders from destroying us from within, and yet, over time, shifts in the percentages and raw numbers of certain immune cells make it more and more difficult to fight off infection.
Our circulatory systems are obviously wonderful and amazing mechanisms in being able to last as long as they usually do while sending blood, nutrients, and oxygen all over our bodies -- but like all physical mechanisms, they are subject to mechanical fatigue and other hazards of long-term operation.
Many people use the word "aging" as a shorthand not just for the mere process of getting older (which is not only inevitable for everything in existence, but something to celebrate -- "getting older", after all, means "experiencing more life"!), but for the physical degeneration that occurs as metabolic, immune, and mechanical side effects take hold as a person ages.
Personally I find this dual use of the word "aging" terribly confusing, and would prefer to allocate a term like "age-related damage", but regardless of what terminology you prefer, it is undeniable that older organisms are more vulnerable than younger organisms in particular ways.
No matter how diligent we are in eating well, visiting the doctor, getting enough exercise, etc., there's still a whole lot of room for error to creep in. The sheer level of diligence required to maintain "optimum" health is beyond many people's capacity -- not because they are "weak-willed" but because there are so many things that don't even show up on medical scans until they're already causing problems.
So while it must be acknowledged that biological organisms have built-in vulnerabilities (without which they might not be able to exist in the first place, considering how delicately intertwined with life-sustaining processes these vulnerabilities are), it also makes sense to look at how older organisms might be spared some of the vulnerabilities they currently deal with.
When I think about present-day human medicine, it looks a lot to me like we're all like goldfish being kept in tiny bowls -- bowls which are, perhaps, emptied and replenished regularly, but still too small and improperly configured to permit optimum health over long stretches of time. Because of this, many of us don't end up reaching even the supposed species maximum (barring future developments) of 120, let alone much older ages.
My vision of future medicine, on the other hand, is one that more closely resembles a large, optimally configured tank with filter mechanisms, plenty of plants, and some level of automation to correct for human error (analagous to how the filter pump consistently circulates water, reducing the need for frequent manual water changes, which can be easily forgotten or put off by distracted humans).
There's a technical aspect to this, of course -- scientists and doctors will need to develop and test the actual mechanisms, which will require both laboratory and creative resources. But there is also a socioeconomic/infrastructure aspect to consider, and I actually see this aspect as being the more difficult of the two to realize.
While medicine can do some amazing things these days (consider how many more people now survive cancer than used to, and how many heart patients would probably be dead if not for pacemaker technology), the best medicine is not accessible (physically or financially) to everyone, and there are a lot of odd political and other "soft" factors acting as "hard" walls between many and the healthcare they need.
This might be a pipe dream, but I would love to see life-sustaining healthcare (for people of all ages, including the very old) considered on par with things like food and water -- that is, not "luxuries", but as necessities.
Returning to the goldfish analogy again, what might my concept of Nigel's life possibilities have been if I'd not had access to the information I did? If I'd not learned that the blackening of his fins was due to ammonia poisoning, I might have presumed he'd simply come preloaded with some weird fish disease. If I'd not learned that goldfish needed more oxygen in their water than, say, betta fish (who can actually gulp air using their labyrinth organ), I might have presumed Nigel was just extremely laid-back when I saw him sitting at the bottom of the tank. And if, Darwin forbid, he'd died the day after moving in with me, I might have gone on thinking that goldfish were just "delicate" and not all that long-lived to begin with except in rare, exceptional cases.
Now imagine I'd learned a little bit about goldfish care (but not a lot), and decided to try swapping out lots of water every day from his small, nonfiltered tank in order to keep his environment fresh. If I was lucky, Nigel might have still gone on to live a long life, but more than likely, he'd have ended up another statistic in the "goldfish are small, short-lived creatures" data pool. I might not have even gone on to research very long-lived fish as I have now, or learned that it is actually common for well-kept goldfish to live 20 years or more.
In short, in the absence of the plentiful, scientifically accurate information I happily had access to, I might have gone on thinking that short lifespans were intrinsic properties of goldfish, rather than the robust, long-lived creatures they actually are when properly cared for.
I don't know to what degree this analogy actually applies to humans, but it certainly seems worth running the experiment!