According to a new study, the coelacanth, a giant strange fish
that has survived since the dinosaur era, can live for 100 years.
These slow-moving, people-sized deep-sea fish, dubbed a "living fossil," are the polar opposite of the "live fast, die young" mantra, growing at an excruciatingly slow rate.
Female coelacanths do not reach sexual maturity until their late 50s, while male coelacanths reach sexual maturity between the ages of 40 and 69, according to the study. Perhaps most strangely, researchers believe pregnancy
in the fish lasts about five years.
Coelacanths, which have been around for 400 million years, were thought to be extinct until they were discovered alive in 1938 off the coast of South Africa
. Scientists previously thought coelacanths lived for about 20 years, but by using a standard technique for dating
commercial fish, French scientists calculated they actually live for close to a century, according to a study published Thursday in Current Biology.
Scientists can only study specimens that have already been caught and killed because coelacanths are so endangered.
Previously, scientists calculated fish ages by counting large lines on a specific coelacanth scale, but the French researchers discovered that they were missing smaller lines that could only be seen with polarized light — the technique used to determine the age of commercial fish.
According to study co-author Bruno Ernande, a marine evolutionary ecologist at France
's marine research institute, polarized light revealed five smaller lines for every large one, and the smaller lines better correlated to a year of coelacanth age — indicating their oldest specimen was 84 years old.
Using the technique, the scientists examined two embryos and determined that the oldest was five years old and the youngest was nine years old, implying that pregnancy in coelacanths, which have live births, lasts at least five years, according to Ernande.
The five-year gestation period is “very unusual” for fish or any animal, according to Harold Walker
of the Scripps Institution of Oceanography, who was not involved in the study.
Even though coelacanths are genetically unrelated and exhibit wide evolutionary differences, Ernande believes they age slowly like other deep-sea dwellers, sharks
and rays. “They may have evolved similar life histories because they share similar type habitats,” he says.
@borenbears is Seth Borenstein
The Howard Hughes Medical Institute's Department of Science Education
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