In the waters of North America's Great Lakes swim creatures whose age may be measured in centuries. New data indicate that the lake sturgeon (Acipenser fulvescens) can live to be 400 years or more — nearly twice as long as previous estimates.
Previously, scientists believed the maximum lifespan of this species to be around 150 years. However, an analysis of four decades of observations of tagged individuals in Lakes Michigan, Huron and others revealed a different picture. The slow growth of large fish led to a revision of their age: females may reach 427 years, males up to 279 years.
Such figures place the lake sturgeon among the longest-living vertebrates on the planet, second only to the Greenland shark. These "living dinosaurs" are descendants of ancient fish whose ancestors lived as far back as the Jurassic period. Some individuals may have been swimming here even before the founding of the United States.
The species' long life changes the approach to its conservation. Restoring populations that have been greatly reduced by overfishing and environmental change will take decades and even centuries. The fish grow extremely slowly, and each generation is of particular importance for genetic diversity.
The study, published in the Journal of Fish Biology, is based on real catch and recapture data from rivers and lakes in the region. The scientists emphasize that the exact age of individual fish has not yet been directly confirmed, but the calculations based on growth rates look convincing.
The discovery is a reminder of how fragile and at the same time resilient freshwater ecosystems are. Caring for such ancient inhabitants requires patience that goes beyond a human lifetime.
