The other, a gene involved in cell growth and repair called proliferating cell nuclear antigen (PCNA), has a copy that slows the rate at which organisms age.

Scorpaenopsis Aleushenensis: over 200 years old

The Aleushen Scorpaenopsis is one of the longest-lived fish, living up to 205 years. These pink or brown fish live in the Pacific Ocean from California to Japan. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed that they grow up to 38 inches (97 cm) long and feed on other animals such as shrimp and small fish.

A scorpaenopsis Aleushin on the California coast

Freshwater pearl clam: over 250 years old

Freshwater pearl mussel is a bivalve that lives mainly in rivers and streams in Europe and North America. According to the World Wildlife Fund (WWF), the oldest known freshwater pearl clam is 280 years old, and these invertebrates live long because of their slow metabolism.

Freshwater pearl clam
Freshwater pearl mussels are also an endangered species. According to the International Union for Conservation of Nature (IUCN), their numbers are declining due to a variety of human-related factors, including destruction and alteration of the river habitats on which they depend.

Greenland shark: 272 + years old

The Greenland shark lives deep in the Arctic and North Atlantic and is one of the largest shark species in existence. Canada's St. Lawrence Shark Observatory says they can grow up to 7.3 meters long and feed on Marine mammals such as fish and seals.

A Greenland shark swims contentedly

In 2016, researchers wrote in the journal that their study of a population of Greenland sharks showed that the sharks lived for at least 272 years, the oldest being about 392 years, and some could live as long as 512 years.

Age estimates can be subject to a degree of uncertainty, but even at 272 years old, these sharks would rank among the longest-lived known vertebrates on Earth. Scientists say an important factor in the Greenland shark's longevity is its very slow growth rate.

Deep-sea tubeworms: 300 + years old

The cold depths of the ocean are an amazing world, full of creatures that are not only hard to see, but some of them have amazing signs of life, and a tubular worm called Escarpia laminata is one of the best.

Tube worm that lives on the sea floor

A 2017 study published in the journal found that the tube-shaped worms, which live on the floor of the Gulf of Mexico, have an average lifespan of more than 300 years, and some have lived for more than 1,000 years,suggesting that they took root in their current habitat as early as the Northern Song Dynasty.

The researchers said that the abundance of food and the absence of predators allowed it to grow without worry and also contributed to its longevity.

Arctic clam: 500 + years old

Arctic clams live in the North Atlantic Ocean. In 2006, scientists caught an Arctic clam off the coast of Iceland, but it died during follow-up studies. On November 13, 2013, scientists published an analysis showing that the true age of the Arctic clam was 507 years old. This means that it was born around 1499 AD, so scientists named the arctic clam after the Ming dynasty.

Arctic clam
Arctic clams grow more slowly than other clams, which is also responsible for their longevity. Most particularly long-lived animals, such as Arctic clams, Greenland sharks and bowhead whales, have low body temperatures or live in cryogenic environments.

Scientists believe that in cold weather, processes such as the production of reactive oxygen species, DNA repair and gene transcription are slowed down, helping animals live longer.