New discoveries about mysterious predatory fish in the ocean

Sharks sleep so silently and slowly deep in the ocean that they are given this nickname .

Although it is one of the largest predatory fish in the ocean, living throughout the Pacific Ocean, the Pacific sleeper shark is little known.

A group of scientists stepped in to create a comprehensive repository of information about this slow shark.

Pacific sleeper sharks are closely related to Greenland sharks. They have similar characteristics and can even interbreed.

Adult Pacific sleeper sharks often like to hang out in the deep regions of the ocean (Photo: NOAA Office of Ocean Exploration and Research).

They can be up to 4.3 meters long. It is speculated that adults living in deeper parts of the ocean may even reach 7m.

It is also suspected that sleeping sharks also possess the same desirable lifespan as their relatives (Greenland sharks are the longest-living vertebrates in the world, with an estimated average lifespan of about 400 years).

However, unlike the Greenland shark, sleeper sharks are underrated, possibly due to their lack of commercial value, the sheer difficulty of accessing their habitat, their low frequency of occurrence, and their lack of commercial value. strict requirements in catching and handling this large animal.

Sleeping sharks are also currently a species listed as decreasing in number and threatened in the IUCN Red List.

Now, one of the most important findings comes from genetic studies showing that, in fact, the number of Pacific sleeper sharks may be much larger than predicted.

Lead author Beth Matta said: "We used to think there were three major species in the genus: the Pacific sleeper shark, the Southern sleeper shark and the Greenland shark. Now we know the Southern sleeper shark have no genetic differences from the Pacific sleeper shark."

They also discovered a lot of evidence about the potential lifespan of sharks, supporting the theory that they can live up to several hundred years.

For example, a study using radiocarbon dating to analyze the irises of this fish found that they had a growth rate twice as fast as the Greenland shark , but still significantly slower Compared to many other fish species, they have a much longer life expectancy than average.

Specimens of Pacific sleeper sharks' irises are used to determine their age (Photo: NOAA Fisheries).

Much evidence also shows that Pacific sleeper sharks have slow growth rates, slow maturation, and long lifespans. . These factors can make them vulnerable to overfishing.