The ancient fish species Coelacanth, known for its “slow living,” can live up to a century with a gestation period of 5 years, according to a new study.
Coelacanth, a fish that has existed since the time of the dinosaurs, matures at a very slow rate, according to research conducted by French scientists published on June 17 in the journal Current Biology, as reported by AP on June 18.
The study found that female Coelacanths do not reach maturity until their late 50s, while males reach reproductive age between 40 and 69 years old.
Referred to as a “living fossil,” the Coelacanth has survived for 400 million years. This species was thought to be extinct until it was unexpectedly discovered in 1938 off the coast of South Africa, astonishing the scientific community of the time.
It is reported that fishermen “accidentally” discovered this species while using specialized Gillnets designed to catch more sharks.
This type of net has been upgraded and integrated with advanced technology, allowing access to very deep water areas, at depths of around 328 to 492 feet (approximately 150 meters) below sea level. Notably, this is also the preferred habitat of the Coelacanth.
The Coelacanth is in such a critically endangered state that scientists can only study deceased specimens.
The Coelacanth was believed to have been extinct for a long time but was surprisingly discovered in 1938. (Photo: AP).
In the past, scientists estimated the age of the fish by counting the large markings on a Coelacanth’s scale. This method previously estimated the lifespan of the Coelacanth to be around 20 years.
However, French scientists discovered that this method overlooked smaller markings only visible under polarized light— a technique used for determining the age of commercially important fish.
Bruno Ernande, a co-author of the study at the French Institute of Marine Research, mentioned that polarized light reveals that each large marking is accompanied by 5 smaller markings. From this, researchers concluded that each small marking corresponds to one year of the Coelacanth’s life. This indicates that the oldest specimen they studied was 84 years old.
Using a similar technique, scientists continued to study 2 Coelacanth embryos, estimating that the largest specimen was 5 years old. Therefore, they concluded that the gestation period for Coelacanths lasts at least 5 years. Coelacanths give birth directly like humans, rather than laying eggs.
A gestation period of 5 years is considered “very unusual” for fish or other animal species, according to Harold Walker from the Scripps Institution of Oceanography (USA). Mr. Walker is not part of the research team.
Despite having no genetic relation and distinct evolutionary traits, Coelacanths share a similar slow maturation rate with deep-sea fish species (such as sharks and rays), according to Ernande.
“They may share a similar evolutionary history because their habitats are alike,” Ernande stated.
The Coelacanth possesses a very unique body structure. It is the only known surviving animal that has joints located within its skull, allowing a clear division between the front and back parts of the skull from the inside.
Scientists explain that the bending at these joints may assist “lobe-finned fish” in opening their mouths wide and swallowing large prey.
The Coelacanth has a very unique body structure. (Photo: Reuters).
The Coelacanth has sharp eyes with a structure known as “tapetum lucidum” (a reflective layer similar to that in cat eyes), allowing it to adapt and evade predators in various natural conditions, including at night.
The Coelacanth inhabits deep water areas and is roughly the size of an adult human, moving slowly and earning the nickname “living fossil.” This fish is nocturnal and grows at an extremely slow pace.
