There are millions of species that have been identified on earth and they have varying lifespans. The average length of life of an organism is one that has interested many scientists over the years. It has been found through observation and testing that some animals have a long life span. Unfortunately, some animals do not live the average lifespan as a result of predators, competition, adverse conditions and disease. Here are five animals with a long lifespan.

1. Macaws

Macaws are large, long-tailed brightly colored parrots. There are about eighteen species that are found in many tropical countries of North and South America. They are known to be quite intelligent, usually found in flocks of ten to thirty. They can live between thirty and fifty years in the wild although this may vary depending on the species. There are species that can survive for more than a century. Charlie, a blue and gold macaw, is thought to be the longest living macaw and is 114 years old.

2. Galapagos Giant Tortoise

The Galapagos Giant Tortoise also called giant tortoises is the largest tortoise species in the world. There are thirteen species of this tortoise and they can grow to a length of more than five feet long and have a weight of more than 500 pounds. They are also quite slow and are often found sleeping during the day. Among all the vertebrates, these tortoises are the longest lived. On average they can live more than one hundred years. It was recorded that one of these reptiles lived for 175 years.

3. Koi

Koi fish are colorful, ornamental domesticated varieties of the common carp which are popular in Japan and eastern Asia. They can be used for decorative purposes in outdoor ponds. There are more than one hundred varieties of this fish. Koi are culturally significant in Japan and they represent love and friendship. Koi have an average lifespan of forty years although they can live for many more years than this. It is thought that the oldest known Koi lived to be 230 years old. To determine the age of fish, the scales are tested as they produce growth rings which are similar to a tree.

4. The Immortal Jellyfish

Turritopsis dohrnii, also known as the immortal jellyfish, is thought to have originated in the waters of Japan but are now found in many oceans. This creature has the unique ability to reset and revert to its earlier developmental stage if it is threatened such as when in physical harm or starvation. Some say it cheats dead as it can reverse its life cycle. When the adults, which measure 4.5 mm wide have reproduced it is thought that they don’t die but rather, transform themselves back into the juvenile polyp state. This ability means that in theory, they can live forever if not eaten by predators or killed in some other way.

5. Greenland Shark

The Greenland shark, also called the gurry shark or the dim shark, is a member of the sleeper shark family, Somniosidae. These sharks are found mainly in the cold waters of the Arctic Ocean. They have a rounded snout, a large body and small fins. It is the longest living vertebrate and can reach a length of seven meters and weigh over 2000 pounds. Scientists estimate that the Greenland shark can live between 250 and 500 years. To determine how old one of the sharks is, the tissue at the center of its lens, which keeps expanding throughout the course of its lifetime, is radiocarbon-dated.