Coelacanth fish live in deep water, are human-sized, slow-moving, and are nicknamed ” living fossils “. This nocturnal fish grows at an extremely slow rate.

Female Coelacanths don’t reach sexual maturity until their late 50s, while males reach sexual maturity at a young age, according to research published in the journal Current Biology on June 17. from 40 to 69.

The strangest thing is that the researchers found that pregnancy in Coelacanth fish lasts about 5 years.

The developmental stages of the “living fossil” fish Coelacanth. Photo: Paris Museum of Natural History

Coelacanth has been around for about 400 million years. This fish is known from fossils and is thought to have been extinct since the Cretaceous period (about 66 million years ago). However, Coelacanth was found alive off the coast of South Africa in 1938.

Scientists have long believed that Coelacanth lived about 20 years. However, using standard techniques for dating commercial fish, French scientists calculated that this strange giant creature actually lived for nearly a century.

The Coelacanth is so threatened with extinction that scientists can only study captured and dead specimens.

Study co-author Bruno Ernande, an evolutionary ocean ecologist at France’s ocean research institute, said the polarized light technique concluded that the oldest specimen of the Coelacanth was 84 years old.

This method also allowed the team to conclude that the fry stayed in the womb for 5 years, much longer than the longest gestation period of mammals (Indian elephants hold the pregnancy record for around 22 months). .

Researcher Harold Walker of the Scripps Institution of Oceanography, who was not involved in the study, said the five-year gestation period was “very strange” for fish or any other animal .