Polar shark discovered in an unusual place. It can live up to 400 years old

Marine biologists were surprised when - as reported by Science Alert - they discovered an unexpected visitor in the Caribbean Sea. Scientists off the coast of Belize were studying tiger sharks, which had changed their behavior and moved from shallow waters surrounding coral reefs to much deeper waters - to a depth of even approximately 2297 feet.

As reported by Science Alert, during one of the voyages, researchers were surprised to see a shark that they initially did not recognize - they initially thought they were dealing with a six-gilled shark, and then with some hybrid of a polar shark with another species of Somniosidae.

Closer examination, however, confirmed that a polar shark had ventured into tropical regions. Its characteristic head and the size and shape of its fins made its identification possible.

The discovery suggests that polar sharks may inhabit a much larger area than previously thought and - something not previously suspected - outside of polar waters they may also live in other places around the world.

Polar sharks have captured the attention of the entire world thanks to research conducted by Prof. Julius Nielsen. This research has proven that these are the oldest known vertebrates on Earth, and the age of the oldest individual was determined in 2016 to be 392 years old (with a margin of error reaching up to 120 years on either side).

These fish are distinguished by their extremely slow swimming pace - they move at an average speed of 0.7 mph, and one third of their body weight is their liver. They spend most of their time at very great depths, reaching 5905 feet, but in the summer they swim closer to the surface.

Despite the low speed of Greenland sharks, their diet is varied - apart from fish and seals, remains of polar bears and reindeer have been found in their stomachs.