Most humans are lucky to see 90. Some animals barely make it past a season. And then there are the biological outliers that scoff at our expectations of aging.
The Greenland shark cruises Arctic depths with the same sleepy pulse it likely had before Napoleon was born. The tuatara of New Zealand, a spiny reptilian relic, can outlive generations of researchers studying it.
But even among these long-living creatures, one freshwater fish from North America manages to feel almost otherworldly.
The bigmouth buffalo, a hulking filter-feeder found in lakes and rivers across the U.S. and Canada, has produced individuals that live for more than 120 years — with one supercentenarian verified at 127.
They may be young in relative terms, but here’s what makes them truly strange. Some populations haven’t seen a single new generation in over half a century. And instead of slowing down, these fish appear to get better with age.
The animal kingdom is no stranger to long lives. But this one rewrites the rulebook.
The Bigmouth Buffalo Is In No Hurry To Grow Its Population
Broad-bodied, olive-toned and often dusted with copper or black speckles, the bigmouth buffalo, or Ictiobus cyprinellus, can grow over four feet long and tip the scales at 80 pounds. Unlike most of its freshwater peers, it’s a filter-feeder with a forward-facing mouth, built more for sipping plankton than chasing prey.
Rather than reproducing regularly like many of its freshwater neighbors, some populations of bigmouth buffalo appear to skip entire decades between successful generations.
In Canada’s Qu’Appelle River system, researchers studying a population of these fish found that most were born before the mid-20th century. Of the 52 individuals observed between 2018 and 2021, only one was hatched after 1997. The rest belonged to just 13 year classes spread over more than a century, according to a February 2023 study published in the Canadian Journal of Fisheries and Aquatic Sciences.
This is observed because the bigmouth buffalo has adapted to rare windows of reproductive success, a strategy known as episodic recruitment. The fish requires very specific environmental cues to spawn successfully, like newly-flooded vegetated waters and a narrow temperature range between 15.5 and 18.3°C.
If any of these factors fall short, the eggs fail to hatch or the larvae are quickly eaten.
To endure these long gaps, bigmouth buffalo have evolved an extraordinary workaround — just outlive the bad years. By living more than a century, they increase their odds of eventually hitting that rare window when conditions align and a new generation can take hold.
But In One Place, A New Generation Hasn’t Been Seen For Over 50 Years
At Rice Lake National Wildlife Refuge in Minnesota, bigmouth buffalo still return each spring like clockwork. As the waters warm, they swim up from the Rice River to spawn among the flooded wild rice beds, just as they have for generations. They lay eggs. The eggs hatch. And for a few weeks, everything looks as it should.
But by midsummer, the young fish are gone.
A September 2024 study published in Scientific Reports surveyed 390 individuals in this population. It was found that 99.7% of the bigmouth buffalo were over 50 years old — many pushing 80 or 90 and some exceeding 100. That kind of age structure isn’t typical of most fish populations.
What it points to is a deep and persistent recruitment gap — essentially, no new generation making it to adulthood in more than half a century. While the reasons aren’t entirely nailed down, likely culprits include high predation pressure from invasive species, poorly managed water levels and unfavorable temperatures.
For now, the Rice Lake population continues to hold steady, buoyed by the remarkable longevity of its oldest members. But with so few young fish making it through the gauntlet of early life, it raises questions about how long the population can sustain itself without help.
The Bigmouth Buffalo Doesn’t Age Like The Rest Of Us
In most animals, the passing decades bring familiar signs of wear, like weakened immune systems, elevated stress and cellular decay. But in the bigmouth buffalo, time appears to move a little differently.
An April 2021 study published in Scientific Reports tracked individuals ranging from 2 to 99 years old — and found no evidence of physiological decline with age in several key systems.
In fact, older buffalo seemed to fare better than their younger counterparts.
They showed lower stress levels, which was measured by a common blood marker (the neutrophil-to-lymphocyte ratio), and exhibited stronger immune function. Instead of an expected breakdown of biological systems, researchers saw what looked more like an upgrade.
Even the length of the telomere, a protective cap that protects the chromosome and an indicator of aging in other species, remained stable over time unless the individuals were stressed.
The reasons for this are still being explored, but the results place bigmouth buffalo in a rare category of vertebrates that may experience what scientists call “negligible senescence” — essentially, aging without the usual deterioration.
In contrast to the human trajectory, where stress and disease tend to accumulate with age, the bigmouth buffalo may be playing a different evolutionary game — one that emphasizes longevity and survival over rapid turnover.
This strategy doesn’t make them invincible. But it does make them unusually well-equipped to persist — so long as the external threats remain in check.
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