| 双语新闻 Bilingual News | 双语对照阅读 分级系列阅读 智能辅助阅读 在线英语学习 |
|
| 双语新闻 Bilingual News | 双语对照阅读 分级系列阅读 智能辅助阅读 在线英语学习 |
| [英文] [中文] [双语对照] [双语交替] [] |
| Scientists recently confirmed that the majority of the buffalofish swimming around this remote desert lake in eastern Arizona are older than a hundred. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| Greenland sharks have the greatest longevity of any living vertebrate, reaching at least 250 years old. |
| 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. |
| “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.” |
| 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. |
| 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. |
| Lackmann says further studies into buffalofish longevity could provide insight into how vertebrates, including humans, can live longer. |
| “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?” |
| 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. |
| 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. |
| “They are still advancing into prime condition at a century old, which is astonishing,” Lackmann says. |
OK阅读网 版权所有(C)2017 | 联系我们