一項新研究顯示，水牛魚格外長壽且它們在八九十歲時身體狀態(tài)最好。釣魚愛好者斯圖爾特·布萊克（Stuart Black）釣過很多魚，但他2019年在亞利桑那州的阿帕契湖釣到他的第一條水牛魚時，他預感這是件特別的事。事實證明，他的直覺是正確的。

Scientists recently confirmed that the majority of the buffalofish swimming around this remote desert lake in eastern Arizona are older than a hundred.
科學家最近證實，在亞利桑那州東部這個偏遠的沙漠湖周圍生活的大多數(shù)水牛魚的年齡都在100歲以上。

The discovery builds on other recent research that has upended beliefs about the little-studied buffalofish, a genus of five freshwater fish species native to North America.
這一發(fā)現(xiàn)建立在最近其他研究的基礎上，這些研究顛覆了人們對水牛魚的看法，水牛魚是一種原產(chǎn)于北美的五種淡水魚屬。

Just a few years ago, scientists thought that these fish, which come in an array of colors from chestnut brown to bluish, only lived into their mid-20s. However, a 2019 study revealed that bigmouth buffalofish could live up to 112 years old, making it the oldest known freshwater teleost, a group of about 12,000 ray-finned fish species found worldwide. Then in January, researchers announced the discovery of a 127-year-old bigmouth in Saskatchewan, Canada.
就在幾年前，科學家們以為這些栗色、藍色的魚只能活到20多歲。然而，一項2019年的研究揭示，大口水牛魚能活到112歲，是已知最古老的淡水硬骨魚，這是一種在全球范圍內發(fā)現(xiàn)的約有12000種的射線鰭魚類。在今年1月，研究人員宣布在加拿大薩斯喀斯溫省發(fā)現(xiàn)一只127歲的大口水牛魚。

Now, the new study, published recently in Scientific Reports, confirmed that two more buffalofish species—the smallmouth buffalo and the black buffalo—can live more than a hundred years, making it the only known genus of animal besides the marine rockfish, Sebastes, that has three centenarian species.
現(xiàn)在，最近發(fā)表在《科學報告》上的這項新研究證實，又有兩種水牛魚——小口水牛魚和黑水牛魚——可以活過一百歲，這使其成為除了海洋巖魚（主要由鯛科成員組成）之外，唯一已知的擁有三種百年物種的動物屬。

For the Arizona study, a few dozen anglers, including Black, caught 222 buffalofish at Apache Lake from July 2018 to July 2023. Twenty three were humanely euthanized and donated to the research team, who estimated the fishes’ ages by removing and analyzing tiny ear stones called otoliths. These calcium carbonate structures, which allow fish to hear and sense vibrations in the water, form a new layer each year that can be read somewhat like tree rings.
在亞利桑那州的研究中，2018年7月至2023年7月，包括布萊克在內的幾十名垂釣者在阿帕契湖捕獲了222條水牛魚。23條被人道安樂死并捐贈給研究小組，研究小組通過移除和分析微小耳石來估計這些魚的年齡。這些碳酸鈣結構使魚類能夠聽到和感知水中的振動，每年都會形成一個新的層，類似樹木的年輪。

The otolith analysis revealed that about 90 percent of Apache Lake’s buffalofishes were more than 85 years old. Researchers aged individuals of all three species studied there—smallmouth buffalo, bigmouth buffalo, and black buffalo—past a hundred years old.
耳石分析揭示，大約90%的阿帕契湖的水牛魚都活過85歲。研究者們估計那里的三種研究物種——小口水牛魚，大口水牛魚和黑水牛魚——的個體年齡都在一百歲以上。

Greenland sharks have the greatest longevity of any living vertebrate, reaching at least 250 years old.
格陵蘭鯊魚是現(xiàn)存壽命最長的脊椎動物，可以活到至少250歲。

What’s more, research has revealed that buffalofish continue to live their best lives into their upper 80s and 90s, with better stress response and immune function relative to younger individuals.
此外，研究表明，水牛魚在八九十歲時仍能保持最佳的生活狀態(tài)，與年輕個體相比，它們應對壓力的反應和免疫功能更強。

“The one takeaway is that buffalofishes do not conform to preconceived notions,” says study leader Alec Lackmann, a fish expert at the University of Minnesota. “They defy expectations.”
明尼蘇達大學魚類專家、研究負責人亞歷克·拉克曼說：“一個結論是，水牛魚并不符合我們常規(guī)的認識。它們的情況出人意料?！?/p>

Buffalofish can go decades between successful reproductions because they require very specific environmental conditions—most of which are still unknown—to procreate. That’s why the fish evolved to live so long: It’s an evolutionary adaptation to account for long periods without breeding, according to Lackmann.
水牛魚的成功繁殖間隔可達數(shù)十年之久，這是因為它們需要非常特殊的環(huán)境條件才能繁殖，而其中大部分條件至今仍不為人所知。這就是水牛魚進化得如此長壽的原因： 拉克曼認為，水牛魚長時間不繁殖是一種進化適應。

In Saskatchewan, where buffalofish can go up to 50 years without producing offspring, the fish only attempt to spawn within a narrow range of water-level fluctuations that may rarely occur.
在薩斯喀斯溫省，水牛魚可以長達 50 年不產(chǎn)后代，這種魚只試圖在狹窄水位波動范圍內產(chǎn)卵，而這種情況可能很少發(fā)生。

Lackmann says further studies into buffalofish longevity could provide insight into how vertebrates, including humans, can live longer. 
拉克曼說，對水牛魚壽命的進一步研究可以深入了解包括人類在內的脊椎動物如何活得更長。

“One of the major outstanding questions about the buffalofishes is how they do it in terms of their amazing longevity. What is their fountain of youth?”
“關于水牛魚的一個主要懸而未決的問題是，它們是如何實現(xiàn)長壽的。它們的青春源泉是什么？”

One strategy may be understanding why older buffalofish are less stressed and have stronger immunity than younger fish, which was confirmed in a 2021 study on bigmouth buffalofish.
其中一個可行策略是弄清楚為什么年長的水牛魚比年輕的水牛魚壓力更小，免疫力更強，這一點在2021年一項關于大口水牛魚的研究中得到了證實。

Older individuals could fight off bacteria better than younger animals. Not only that, the elderly fish had a lower ratio of neutrophils to lymphocytes in the blood, an indication of lower stress levels.
年老的個體能比年輕的動物更好地對抗細菌。不僅如此，老年魚的血液中中性粒細胞/淋巴細胞的比例更低，這是壓力水平較低的表現(xiàn)。

“They are still advancing into prime condition at a century old, which is astonishing,” Lackmann says.
拉克曼說：“它們在百歲年紀仍處于身體最佳狀態(tài)，這令人驚訝。”

英文來源：國家地理

編輯：董靜