The African coelacanth, a rare species that has remained almost the same for the past 400 million years, has a lifespan of about 100 years, about five times longer than previously thought, according to a yesterday (June 17) in. published article Current biology. The researchers used polarized light microscopy to examine the scales of 27 fish caught between 1953 and 1991 and, based on the structural patterns in the specimens, estimated that the individuals were between the ages of 5 and 84 years old.
“[The] Coelacanth seems to have one of the, if not the slowest, life stories among marine fish and is similar to that of deep-sea sharks and roughies, ”says co-author of the study Kélig Mahé from the North Sea Fisheries Research Unit in Boulogne-sur-Mer, France BBC News. “This new information on the coelacanth biology and life history is essential to the conservation and management of this species.”
The African coelacanth Latimeria chalumnae, was described in 1938 and is one of only two living species of coelacanth ever identified. It can grow up to two meters long, gives birth to live young, and is classified as critically endangered by the International Union for Conservation of Nature (IUCN).
Researchers have typically examined the ages of these fish using light microscopes to count small lines on the animals’ scales that, like tree rings, represent growing seasons and can thus be used as a proxy for age. This method has historically resulted in an estimated coelacanth lifespan of around 20 years.
Mahé and colleagues found that polarized light microscopy could reveal many more, thinner ridges that could also represent different growth periods. Using this technique, they concluded that the true lifespan was likely closer to 100 years.
As part of their study, team members analyzed the scales of the embryos and estimated that they were around five years old, suggesting that “the gestation period is at least 5 years, as opposed to the 1 to 2 years suggested in previous studies “, The researchers write in their newspaper.
Such a long gestation period is “very strange for any animal,” Harold Walker of the Scripps Institution of Oceanography told the Associated Press.
The team’s results could help protect the coelacanth, says study co-author Bruno Ernande from the University of Montpellier BBC News. “A very important framework for conservation measures is to be able to assess the demographics of the species,” he says. “With this new information we can judge it better.”