The fish that can live 300 years is the Greenland Shark.
The Greenland Shark is considered to be the longest living fish that is able to live 300 years and even up to 500 years.
Greenland Sharks are found in the cold and deep Arctic as well as North Atlantic and they are the longest living vertebrates that are known.
Other fish that live extraordinary long lives are the rougheye rockfish that can live over 200 years and the orange roughy fish, which can live around 200 years.
The Greenland shark, also known as the grey shark or gurry shark, is a large shark of the family Somniosidae, closely related to the Pacific and southern sleeper sharks.
Greenland sharks also known as (Somniosus microcephalus) live for 200 years to 250 to over 500 years due to an extremely slow metabolism, cold Arctic habitat, and minimal tissue wear-and-tear.
As the longest-living vertebrates, Greenland sharks thrive in deep, freezing waters, maturing slowly—around 150 years old—and growing only 1 cm per year.
There are some early Inuit legends that claim Greenland sharks have attacked numerous kayaks, but the reality is that there is not one documented case of such an encounter.
Along with their close relative, the Pacific sleeper shark (Somniosus pacificus), Greenland sharks are the only shark on earth that can handle year-round icy conditions.
While the porbeagle shark can tolerate temperatures as cold as 2 degrees C (36 degrees F), Greenland sharks happily bask in water at -1.8 degrees C (29 degrees F).
Greenland sharks are also known to eat and consume polar bears, with remains of young bears discovered in their stomachs.
While Greenland sharks are primarily scavengers, these sharks are opportunistic predators capable of eating sick, young, or deceased polar bears.
Greenland sharks also are massive, slow-moving predators that may hunt them from below in the Arctic ice.