Coelacanth dates back about 400 million years and was once thought to have gone extinct about 60 million years ago, but in 1938, fishermen discovered living organisms while fishing, so it is also called "living fossils".
A new study published in CurrentBiology points out that while coelacanths have lived in the ocean for hundreds of millions of years, their lifespan and gestation period are much longer than we thought.
It is believed that the first appearance of coelacanth was in the Devonian Period (405 million years ago - 350 million years ago), and its close but extinct suborder fanfin fish species are more believed to be the ancestors of terrestrial vertebrates.
However, because scientists have not found it in the formations after the Cretaceous Period (145 million years ago – 66 million years ago), the species has bid farewell to the world and gone extinct.
The speartail is the only species of coelacanth in the order Speartail and is the only living total fin fish. It was thought that the total fin fish had become completely extinct, but in 1938 fishermen found live bodies while fishing, and they were successfully caught in the same area many times.
In the new study, the researchers analyzed the largest set of coelacanth specimens collected to date (27 fish in total). The specimens ranged in age, and according to the team's analysis, the oldest specimen was 84 years old.
In addition, the researchers found that females do not mature sexually until about 55 years of age, while male coelacanths mature sexually at ages 40 to 69. What is even more strange is that the gestation period of coelacanth is about 5 years.
The researchers said we found that the maximum lifespan of coelacanths is 5 times that of what was previously thought, about 100 years old. However, long-lived species tend to have a slow life history and relatively low fertility, and are highly susceptible to natural or human disturbances due to their extremely low turnover rates.
While the coelacanth has a unique life history, it may be more threatened than expected. Therefore, this new information about the biology and life history of coelacanth is essential for the conservation and management of this species.