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Longevity Secrets from the Five Longest-Lived Marine Animals 五大最长寿海洋动物的长寿秘诀

2021-12-23艾莉森·盖伊译/张燕

英语世界 2021年12期
关键词:虎鲸海绵秘诀

艾莉森·盖伊 译/张燕

Feeling stressed out by the frantic pace of modern life? Meet five ocean-going animals who have mastered the art of slow living—so slow, in fact, that they’re among the oldest creatures on earth. From raising helpful sons to evading predators with snot (yes, snot), learn about the strategies these longevity champions use to stay alive.

5. “Granny” the Orca

Claim to fame: Oldest orca

Age: 104 years

Longevity secret: Family life

In killer whale society, mother really does know best. A matriarch, usually the oldest female, leads a family pod consisting of her sons, her daughters, and her daughter’s offspring. “Granny,” the leader of the J pod—an extended family of whales that roam the coastline from Alaska to California—may be the oldest matriarch of them all. Based on the age of her offspring, researchers estimate that Granny has been around for 104 years.

Part of Granny’s secret could be her species’ peaceful, family-focused life. Throughout their entire lives, male orcas remain so intensely bonded to their mothers that they swim only a body length away from her more than 40 percent of the time. These enormous but gentle momma’s boys help out around the pod by looking after their younger relatives, giving the matriarch more time and energy to feed, rest, and reproduce.

Blessed with helpful sons and the second-biggest brain of any marine mammal, female orcas like Granny may simply be healthier and happier than their counterparts in less-peaceful animal societies.

4. Bowhead Whale

Claim to fame: Oldest mammal

Age: Over 200 years

Longevity secret: Stay healthy

In 2007, Inupiat hunters in Alaska found an antique harpoon head lodged in the blubber of a recently killed bowhead whale. That particular brand of harpoon hadn’t been manufactured since 1885—indicating that the whale had survived a whaler’s attack in Victorian times and gone on to live for another 130 years.

Since then, dating of the amino acids in bowhead eyes has revealed that they can live to be over 200 years old, making them the longest-lived mammal by about a factor of two.

These whales not only attain great age, but they remain disease-free until much later in their lives than humans do. Curious as to how they manage this feat, researchers sequenced the bowhead genome and discovered changes in their DNA  related to cancer, aging, and cell repair. This suggests that these sprightly cetaceans have evolved special resistance to age-related disease and decline.

3. Orange Roughy

Claim to fame: Among the oldest marine fishes

Age: 157 years

Longevity secret: Avoid predators

The orange roughy, a reddish-orange fish that dwells 500 to 6,000 feet below the sea’s surface, takes its sweet time growing and maturing. They only start to reproduce between 20 and 40 years of age, but can live to be older than 150 years.

Before getting a rebrand to appeal to human customers, orange roughy used to be called “slimeheads” for an obvious reason: they exude mucus from channels on their heads and bodies. Gross as it sounds, these slimy organs actually detect tiny changes in water pressure, helping orange roughy excel at the art of predator avoidance.

Unfortunately, orange roughy aren’t able to avoid fishing nets.

Throughout most of their range, they’ve been severely overfished. Since they take so long to grow and reproduce, it may be decades before their populations can recover. The deep-sea trawling equipment that’s used to catch them also bulldozes corals and scoops up many non-target species, making this fishery doubly unsustainable.

Rather than eating orange roughy, it’s better to choose sustainable seafood and admire slimeheads where they belong: peacefully growing old a mile below the waves.

2. “Ming” the Ocean Quahog

Claim to fame: Oldest animal (verified)

Age: 507 years

Longevity secret: Stay young at heart

Pity poor Ming. Born sometime during the Ming Dynasty, this ocean quahog met its end when researchers were dredging the seabed in North Iceland. By counting its growth bands and dating the carbon in its shell, scientists determined that this clam settled onto the seafloor approximately 507 years ago.

Ming, and other long-lived clams like it, continue to grow but don’t appear to grow old—the bivalve equivalent of a 90-year-old human with the body and mind of a 20-year-old.

1. Antarctic Sponge

Claim to fame: Oldest animal (unverified)

Age: 15,000 years

Longevity secret: Take things slow

Snow-white and shaped like a beer barrel, one individual of the Antarctic sponge species Anoxycalyx joubini may be the oldest living animal yet discovered—by a long shot. Taking into account its size and the average growth rate of its species, one researcher calculated that this enormous specimen could be up to 15,000 years old.

Just how old is 15,000 years? When this sponge was just a baby, wooly mammoths still roamed the world, humans had yet to colonize the Americas beyond northern Canada, and the basins that would become the Great Lakes were still almost entirely buried beneath a miles-thick ice sheet.

Even at half its estimated age, Anoxycalyx joubini would still be the oldest animal on earth, and among the oldest of all organisms, period. By contrast, the famous bristlecone pines in California live a measly 5,000 years.

疯狂的现代生活节奏令你压力山大?来认识一下五种掌握了慢生活艺术的海洋动物——它们的生活节奏如此之慢,令它们得以跻身最长寿的地球生物之列。从养育儿子来帮助自己,到靠鼻涕(是的,鼻涕!)躲避掠食者,来学学这些长寿冠军延续生命的策略吧。

5. 虎鲸“老奶奶”

成名原因:最长寿的虎鲸

年龄:104岁

长寿秘诀:家庭生活

在杀人鲸(虎鲸)的世界,妈妈最博学。女族长通常是年纪最大的雌鲸,带领着由儿子、女儿及女儿的后代组成的大家族。杀人鲸族群中的J家族足迹遍布自阿拉斯加至加利福尼亚海岸线,其头领“老奶奶”可能是年纪最大的族群首领。根据她后代们的年龄推算,研究人员认为她的年纪在104岁左右。

“老奶奶”的长寿秘诀可能部分源于这一种群以家庭为核心的平静生活方式。雄鲸一生中超过40%的时间都与母亲形影不离,就在与其母距离仅一个身位的范围内活动。这些体形巨大但性情温柔的“妈宝男”帮助照顾比他们年幼的亲人,让女族长有更多时间和精力进食、休息和繁殖。

依靠儿子们的帮助以及自身拥有的海洋哺乳动物中第二大的大脑,像“老奶奶”这样的雌性虎鲸得以比不那么和平的动物社群中的那些同侪生活得更健康、更快乐。

4. 弓头鲸

成名原因:最长寿的哺乳动物

年龄:超过200岁

长寿秘诀:保持健康

2007年,阿拉斯加的因纽特猎手们在一头刚刚被猎杀的弓头鲸的鲸脂内发现了一枚古老的鱼叉头。这个牌子的鱼叉自1885年起就不再生产了,由此表明,这头鲸鱼扛过了维多利亚时代那一波捕鲸人的猎捕后又活了130年。

从那时起,科学家开始对弓头鲸眼中的氨基酸进行年代测定,结果表明,它们可以活到200岁以上,这使它们成为寿命最长的哺乳动物,大约是哺乳动物平均寿命的两倍。

这些鲸鱼不仅长寿,而且一生中保持身体完全健康的时间远超人类。它们是如何做到这一点的?出于好奇,研究人员对弓头鲸的基因组进行了测序,发现了与癌症、衰老和细胞修复有关的DNA变化。这表明,生机勃勃的弓头鲸已进化出特殊能力对抗与年龄相关的疾病及衰弱。

3. 长寿鱼(橙连鳍鲑)

成名原因:最长寿的海洋鱼类之一

年龄:157岁

长寿秘诀:避开捕食者

长寿鱼身体呈橙红色,在海平面以下500至6000英尺的区域生活,充分享受成长和成熟的好时光。它们在20岁到40岁之间才开始繁殖后代,却可以活到150岁以上。

在被重新命名以吸引人类顾客之前,长寿鱼曾被称为“黏头鱼”,原因显而易见:它们会从头部和身体的凹缝处分泌出黏液。尽管听起来很恶心,但实际上这些黏糊糊的器官能够监测水压的细微变化,助其在躲避捕食者方面表现出色。

不幸的是,长寿鱼无法躲避渔网。

长寿鱼在生活的大部分地区都遭遇到严重的过度捕捞。由于它们需要很长时间来生长和繁殖,它们的数量可能要数十年才能恢复。用于捕捉它们的深海拖网设备在捕捞时还会推平珊瑚礁,铲起许多并非捕捞目标的物种——这种渔业方式因而更加不可持续。

与其吃长寿鱼,不如选择食用那些可持续增长的海鲜,同时尊重棘鲷科鱼类的生存方式:在海浪以下1英里的地方安然老去。

2. 海洋圆蛤“明”

成名原因:最长寿的动物(已证实)

年龄:507岁

长寿秘诀:保持心态年轻

“明”实在可怜。这只海洋圆蛤出生于中国明朝年间,却在研究人员疏浚冰岛北部海床时遭遇灭顶之灾。通过计量其外壳生长纹的数量及测算外壳中所含碳元素的年代,科学家们确定,这只圆蛤大约在507年前就在海底定居了。

明,以及其他同样长寿的蛤蜊,可持续生长却似乎不会变老——这一双壳贝相当于擁有20岁年轻人身心的90岁老人。

1. 南极海绵

成名原因:最长寿的动物(未证实)

年龄:15000岁

长寿秘诀:慢生活

通体洁白如雪,形如啤酒桶——南极海绵极有可能是迄今发现的最古老的存活动物,这一物种名为“火山海绵”。根据这一个体的大小和该物种的平均生长速度,一位研究人员计算出,这个巨大样本的年龄可能高达15000岁。

15000岁到底有多老?当这个海绵还是婴儿时,长毛猛犸象仍在世界各地游荡,美洲的人类还只生活在加拿大北部地区,而今天五大湖区形成前的那些盆地还几乎完全埋没在数英里厚的冰盖下。

哪怕实际年龄只有估计的一半,这种海绵无疑仍是地球上最长寿的动物,也绝对位居最长寿生物之列。相比之下,著名的加利福尼亚狐尾松的寿命不过区区5000年。

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