In this world some animals life span might seems very short while others are reasonable long when compared to other animal species. However, the average life expectancy of a given animal is determined by factors such as genetic make up, metabolic rate, body size, age of sexual maturity etc. It is important to note also that some domesticated animal can live longer or shorter than if they were living in their natural environment (habitat). The reason for this may due to conditions such as new life style, change of diet, disease, predator (absent), etc. Therefore, in spite of the fact that many of these values given in the list below are based on records taken from various sources, it should not be seen as the absolute maximum lifespan.
Following is the list of Top 10 Longest Living Animals of the World:
1) Quahog (marine clam) : Among the longest-lived marine species in the world, ocean quahogs grow slowly and have low reproduction rates, making them relatively unproductive and unable to support high levels of fishing. The hard clam, also known as a quahog (or quahaug), round clam, or hard-shell clam, is an edible marine bivalve mollusk which is native to the eastern shores of North America, from Prince Edward Island to the Yucatan Peninsula. The hard clam is the longest living animal, the record is 405-410 years.
2) Giant Tortoise : Giant tortoises are characteristic reptiles of certain tropical islands. Giant tortoises once occurred on all continents, except Australia and Antarctica. However, the arrival of human beings and their rapid colonization of the earth meant that the giant tortoises, large, tasty, and easy to kill, were quickly hunted to extinction anywhere where people lived. Often reaching enormous size—they can weigh as much as 300 kg (660 lbs) and can grow to be 1.3 m (4 ft) long—they live, or lived, in the Seychelles, the Mascarenes and the Galapagos. Giant tortoises are among the world's longest-living animals, with an average lifespan of 100 years or more.
3) Greek Tortoise : This is also longest-lived species in the world. Greek tortoise is one of five species of Mediterranean tortoise family. Greek Tortoise habitat is North Africa, southern Europe and southwest Asia. The life span of Greek Tortoise is 100-110 years.
4) Killer Whale : Killer whale, also referred to as the orca whale or orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas. Killer whales as a species have a diverse diet, although individual populations often specialize in particular types of prey. Killer whales have a lifespan of 25 to 90 years, with females living longer than males.
5) European eel : The eel is a long, thin bony fish of the order Anguilliformes. Because fishermen never caught anything they recognized as young eels, the life cycle of the eel was a mystery for a very long period of scientific history. The average life span of European eel is 10 – 20 years. The maximum reported age for a specimen kept in aquarium is 85 years.
6) Lake sturgeon : The great Lake Sturgeon is a North American temperate freshwater fish, one of about 20 species of sturgeon. Lake sturgeon are the only sturgeon species endemic to the Great Lakes basin and are the largest freshwater fish indigenous to that system. The typical life-span of lake sturgeon is 55 years for males and 80-150 years for females.
7) Sea anemone : Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are Cnidarians, which means that they simply do not age, thus having the ability to live indefinitely. On average anemones usually live only 50-70 years, but this is usually due to falling prey to predators. Or, some other anemones live up to a decade.
8) Elephant : Elephants are large mammals of the family Elephantidae and the order Proboscidea. Traditionally, two species were known, the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus). Elephants are herbivores and they can be found in numerous habitats, including savannas, forests, deserts and marshes, and prefer to stay near water. Elephants are considered to be keystone species due to the impact they have on their environments. An Elephant has a Lifespan very similar to Humans in the wild, their average is about 50-60 years but they sometimes make it to their 70s.
9) Freshwater mussel : A mussel is a relatively simple animal enclosed by two shells connected by a ligament. The shells are formed largely out of calcium carbonate that has been extracted from the waters where mussels live. Freshwater bivalves are one kind of freshwater molluscs, along with freshwater snails. They are bivalves which live in freshwater, as opposed to saltwater, the main habitat type for bivalves. Freshwater mussels are extremely variable with respect to life span, coloration, and size. For example, some species live for only 10 years and others may live for as long as 100 years.
10) Whale Shark : Whale Shark may be one of the longest living animals in the world. The whale shark is a slow-moving filter feeding shark and the largest extant fish species. The largest confirmed individual had a length of 12.65 meters (41.50 ft) and a weight of more than 21.5 metric tons (47,000 lb). The species originated approximately 60 million years ago. The whale shark is found in tropical and warm oceans and lives in the open sea with a lifespan of about 70-80 years.