Koi fish (Cyprinus rubrofuscus) are actually a carp, as well as a distant cousin to the goldfish. People love to collect koi in outdoor ponds for their bright and pretty colors. On average, koi will live 20 to 30 years. But, Hanako, a koi born in 1791, lived for 226 years!
Koi can grow relatively large. The largest recorded koi fish was four feet long and weighed 91 pounds. Koi are vulnerable because their bright colors attract prey, but they are a durable species that can survive harsh climates and conditions. Interestingly, they are rather intelligent. Koi can be trained to respond to sounds or eat to out of hands. The koi fish is indigenous to Central Europe and Asia. They were first domesticated in East Asia and given their name which means “brocaded carp.”
Ocean Quahog Clam
The only thing that might possibly live longer than a Greenland shark is this clam. In 2006, researchers discovered an ocean quahog clam specimen that was estimated to be 507 years old. The mollusk made it into the Guinness Book of World Records and was dubbed Ming, named after the Ming dynasty (1368 – 1644) which was in power when the clam first formed. The researchers used carbon dating and ring-counting to determine its age.
Unlike other clams that live just beneath the soil, ocean quahog clams (Arctica islandica) live deep down where they’re less susceptible to predators. These clams are one of the longest living organisms in the world and can live for at least 200 years. Most quahogs are three to four inches in size and grey in color. They are also known as Icelandic cyprine, mahogany clam, black quahog, and black clam.
Sea Sponge
This creature laughs in the face of a human lifespan. It outlives a person by more than 100 times! Even the amazing longevity of the hearty tortoise is a blip on the timeline compared with a sea sponge. These colorful organisms that are found ornamenting coral reefs, or any ocean floor surface, survive for a mind-boggling 2,300 years. Porifera, its scientific name, is a complex critter of the animal kingdom.
Though they are often written off as a plant because they don’t move and lack a nervous system as well as organs, they are a multicellular organism that consumes oxygen and food. Some sponges are even carnivorous. They come in all sizes, but the largest known sponge is as big as an SUV. It’s 12 feet long and 7 feet wide living just north of the Hawaiian Islands. It is, quite possibly, the world’s largest living animal.
Australian Lungfis
This fish can easily outlive a human, even a centenarian. However, most Australian lungfish live for about 25 years. One lungfish, called Granddad, held in captivity at Chicago’s Shedd Aquarium, lived to 80 years old. Granddad was an adult when it was collected in 1933. It died when the aquarium euthanized it in 2017.
This species has been around forever. Quite literally, fossil records date the Australian lungfish (Neoceratodus forsteri) back 380 million years. This eel-like prehistoric species that swam the rivers while the dinosaurs roamed, has lived in its current form for 100 million years, making it one of the oldest living vertebrates on the planet. One unique aspect to its form is an extremely rare evolutionary trait, a single dorsal lung that allows it to breathe air, hence its name. Amazingly, the Australian lungfish can live several days out of the water. It is native to the rivers of Southeast Queensland.
Olm
This little guy is a salamander that can live more than 100 years! On average an olm (Proteus anguinus) lives 70 years. That’s one long-living amphibian! Its slithering snake-like body grows to only 12 to 16 inches in length. It lives in Central and Southeastern European underwater caves, and, like its cave-dwelling peer, it’s blind as a bat. Luckily, it’s exceedingly adapted to its dark habitat. So much so, that the olm’s other senses, especially smell and hearing, are extremely acute. Olm have lived in caves of Slovenia and Croatia for over 20 million years.
Recently, chemical pollutants have been leaching into the caves. Also damaging olm populations are black market species collectors. As a result, the olm is vulnerable to extinction. Like a frog, the olm matures from a tadpole, but like a fish, it never leaves the water. In the safety of dark underwater caves, the olm has few predators and feeds on small critters like worms, insects, larvae, and snails.