5 AGELESS ANIMALS THAT DO NOT GROW
It’s indeed an odd world folks! While men would want to live young forever, the gift or would we say blessing or privilege… Okay let’s say nature. The nature of immortality and agelessness is bestowed upon some animals.
So, facts Friday today would be unwrapping 5 out of such animals!
As far as multicellular animals go, marine sponges are as simple as they come. They don’t possess the common elements that other animals (like us) have in abundance. They have no internal organs, digestive tracts, or nervous and muscular systems.
Yet a marine sponge specimen has been found to be at least 11,000 years old, with some studies suggesting the potential life span of these creatures to be in the hundreds of thousands of years. The key to their longevity may lie in their simplicity.
Andrey Lavrov and Igor Kosevich, biologists who studied marine sponges’ abilities, found that when the sponges were subjected to tissue dissociation (by mechanically or chemically separating the cells from one another), the sponges were able to re-form into their original shape.
The biologists reported, “In a number of cases, such multicellular aggregates may result in a full reconstruction of an animal’s initial organization.” These amazing regenerative abilities render these creatures nearly ageless.
2. Planaria (Flatworm)
Our school classes taught us about the special regenerative powers of the flatworms, unassuming creatures that harbor the ability to regrow into two healthy flatworms if cut in half. Recently, a lab at MIT performed an experiment that regrew an entire flatworm from a single cell. But one cause of this remarkable feat may not have been mentioned in our high school classes.
Dr. Aziz Aboobaker of The University of Nottingham commented:
Usually when stem cells divide—to heal wounds or during reproduction or for growth—they start to show signs of aging. This means that the stem cells are no longer able to divide and so become less able to replace exhausted specialized cells in the tissues of our bodies.Planarian worms and their stem cells are somehow able to avoid the aging process and to keep their cells dividing.
Due to this cellular youth, flatworms defy aging, making it difficult to accurately measure a flatworm’s life span.
This creature is only about 2.5 centimeters (1 in) high and treelike. To understand its place on our list, we need to understand the concept of senescence, which is the increase in
mortality rate as a creature gets older.
For example, humans are more likely to die the older we get. However, the Hydra does not have this increase in mortality. (Except for one species, Hydra oligactis. Sorry, buddy.)
They accomplish this feat three distinct types of stem cells, which are initially undifferentiated and can eventually become many different specialized cell types. These stem cells are actively renewing the body of the
Hydra and thus fighting off any aging process that could lower their mortality rate.
In a laboratory setting, it’s estimated that 5 percent of Hydra could live up to 1,400 years this process.
4. Ocean Quahog Clam
This marine bivalve mollusk is special because it is exceptionally easy to determine the creature’s age. Like a tree, its life span is recorded in the growth rings of its shell. Even more, those rings offer insight into its life—with wide rings showing a year of plentiful food and narrow rings showing a scarcer time.
Due to this trait, one ocean quahog was dated to 507 years old—the oldest of its kind ever found. This would put its original birthday sometime in 1499.
The secret to this longevity is linked to the quahog’s unusually thin production of reactive oxygen species, which are unstable and oxygen-holding molecules (aka free radicals). Buildup of these molecules can cause damage to DNA , RNA, and proteins and result in cell death.
Due to the quahog’s attenuated amount of these reactive oxygen species, it is able to fight off a common source of aging and live for many centuries. The 507-year-old quahog, named Ming, only met its end because it was frozen after its capture to allow researchers to properly determine its age. In all likelihood, it could have lived for much longer.
5. Turritopsis Dohrnii (Jellyfish)
Imagine that we could decide on a whim to reverse our aging at any point in our lives. Our
hair would get less gray, our wrinkles would disappear, our bodies would get stronger, and our metabolism would increase. We’d be like teenagers again and then like children and, finally, like babies.
Then we’d start aging again from the beginning, living our lives a second time none the worse for wear. This is the exact situation of the Turritopsis dohrnii , the immortal jellyfish . At any point in its life, the jellyfish can reverse aging in a process known as transdifferentiation, revert to its earliest form, and then continue living from there. So far as we know, this process can continue without end.
This mechanism can be triggered by anything from mutilation to old age, starvation, or disease. If left to their own devices, these jellyfish will rejuvenate about 10 times over the course of two years.
Sometimes, these events happen less than a month apart. Also a proficient hitchhiker, this everlasting jellyfish has spread to every ocean in the world by hitching rides on cargo boats.