A tiny jellyfish named Turritopsis dohrnii is capable of living forever, Motherboard reports. Only discovered in 1988, the organism can regenerate into a polyp—its earliest stage of life—as it ages or when it experiences illness or trauma.
The hydrozoan Turritopsis dohrnii, an animal about 4.5 millimetres wide and tall (likely making it smaller than the nail on your little finger), can actually reverse its life cycle. It has been dubbed the immortal jellyfish.
Jellyfish Lifespan
Most jellyfish live one to three years, but certain species can live from days to decades. Jellyfish have complex life cycles, beginning with fertilized larvae floating in the ocean. The larvae sink and attach to the seabed or coral reefs, from there they develop into 'polyps'.
The jellyfish Turritopsis nutricula is biologically immortal and could, under ideal conditions, live for 1000s of years. After sexually reproducing, this jellyfish can revert back to the immature polyp stage (back into a “child”). The jellyfish can still die due to predation, but aging is not a problem for it.
How long does the immortal jellyfish live? Potentially forever. Which gets more impressive considering these creatures have been floating through the oceans long before the dinosaurs went extinct (66 million years ago) – it's biologically possible for a single immortal jellyfish to have been alive for this entire time.
To date, there's only one species that has been called 'biologically immortal': the jellyfish Turritopsis dohrnii. These small, transparent animals hang out in oceans around the world and can turn back time by reverting to an earlier stage of their life cycle.
However, because jellyfish are soft-bodied and almost all water, jellyfish fossils are incredibly rare. Of those that do exist, the oldest-known jellyfish fossils, found in Utah, date to 505 million years ago and have enough detail to show clear relationships with some modern species of jellyfish.
Can jellyfish feel pain? Jellyfish don't feel pain in the same way that humans would. They do not possess a brain, heart, bones or a respiratory system. They are 95% water and contain only a basic network of neurons that allow them to sense their environment.
Although many species of jellyfish have some capacity to reverse aging and revert to a larval state, most of them lose this ability once they reach sexual maturity. However, Turritopsis dohrnii appears to be the only known species able to repeatedly revert back into a larval stage even after sexual reproduction.
They can die from starvation if there is no food around and they haven't reached their mature state. just like other living creatures. They eat things like plankton and other small marine life that is easy for them to scoop up. If their food source is effected in any way, it is possible for them to die.
How long have jellyfish lived in the ocean? This jellyfish fossil is from the Cambrian period, more than 500 million years ago. It was found buried in Utah —an area that used to be underwater, covered by the ocean. Fossil jellyfish are rare because they have no bones or other hard parts to turn into fossils.
Instead of a single, centralized brain, jellyfish possess a net of nerves. This “ring” nervous system is where their neurons are concentrated—a processing station for sensory and motor activity. These neurons send chemical signals to their muscles to contract, allowing them to swim.
An immortal species of jellyfish has double copies of genes that protect and repair DNA. The finding could provide clues to human ageing and age-related conditions. Jellyfish start their lives as drifting larvae. They eventually attach to the seafloor and develop into sprout-like polyps.
Throughout their lifecycle, jellyfish take on two different body forms: medusa and polyps. Polyps can reproduce asexually by budding, while medusae spawn eggs and sperm to reproduce sexually.
In response to physical damage or even starvation, they take a leap back in their development process, transforming back into a polyp. In a process that looks remarkably like immortality, the born-again polyp colony eventually buds and releases medusae that are genetically identical to the injured adult.
The percentage of genetic similarities between humans and animals does vary: chimps, 97% similar; cats, 90%; cows, 80%; mice, 75%; fruit flies, 60%, and jellyfish, 60%.
Immortal jellyfish reproduce both sexually and asexually, but it is not hermaphroditic. The sexually mature medusa stage which reproduces by the spawning and fertilization of eggs with sperm, while the sexually immature polyps reproduce by budding.
Though jellyfish do not have a brain, they are incredibly smart and adaptable. For more than 500 million years, they've been bobbing around almost all the world's oceans, both close to the water surface as well as in depths of up 700 meters. The jellyfish is the world's oldest animal.
Jellyfish are eaten by seabirds, turtles, and crabs. Grey triggerfish, ocean sunfish, seabirds, turtles, whale sharks, crabs, and whales eat jellyfish naturally. However, the main predators of jellyfish are usually other different types of jellyfish.
Jellyfish are not very smart. “They have very simple sensory organs, and no brain to process any information,” says marine biologist Stein Kaartvedt. Which is why it's so interesting that, off the coast of Norway, scientists have observed what they're calling “apparent social behavior” in the helmet jellyfish.
Jellyfish are usually either male or female (with occasional hermaphrodites). In most cases, adults release sperm and eggs into the surrounding water, where the unprotected eggs are fertilized and develop into larvae.
Lacking brains, blood, or even hearts, jellyfish are pretty simple critters. They are composed of three layers: an outer layer, called the epidermis; a middle layer made of a thick, elastic, jelly-like substance called mesoglea; and an inner layer, called the gastrodermis.
The most commonly available species to be kept as a pet jellyfish are Moon Jellyfish (Aurelia Aurita).
Natural Predators
Among the predators of the jellyfish, the following have been identified: ocean sunfish, grey triggerfish, turtles (especially the leatherback sea turtle), some seabirds (such as the fulmars), the whale shark, some crabs (such as the arrow and hermit crabs), some whales (such as the humpbacks).