Turritopsis dohrnii : AKA the immortal jellyfish, the only animals to truly achieve biological immortality

Every organism on the planet has a lifecycle, after which they die. From small and medium sized animals to giants, everyone has to die. But what if you i tell that there is a creature which is actually immortal and cannot die, thank to it's regenerative abilities?!. Today we are going to learn about the one of the few known immortal creatures on the planet, belonging from the species of jellyfish which is known to achieve the state of biological immortality. These are called "Turritopsis dohrnii" or most commonly referred and known as the "Immortal Jellyfish". let's found about what they are and what exactly makes them an immortal creature. Let's go.

 Turritopsis dohrnii (Immortal Jellyfish)

General Info

Immortal jelly fishes are very tiny organisms which were discovered in the Mediterranean sea in 1883 and were studied in around the time of 1990s. As their name suggests, they are known for their infinite lifespan. These jelly fishes are found all over the world, especially in regions with warm water. 

The key to an everlasting life, as it turns out, is not just about living for a really long time. It’s all about maturity, or rather we say, the lack of it. The immortal jellyfish propagate/grows and then, faced with the normal life path of dying, they opt instead, to revert to a sexually immature stage so that they can re-start their life.

Physical Characteristics

The immortal jellyfish is bell-shaped, with a maximum diameter of about 0.18 inches (4.5 mm) and is about as long as it is wide. The mesoglea in the walls of the bell is uniformly thin, except for some thickening at the apex. The relatively large stomach is bright red and has a cruciform shape in cross section. Young specimens 1 mm in diameter have only eight tentacles evenly spaced out along the edge, whereas adult specimens have 80–90 tentacles. 

The immortal jellyfish is free-living in the plankton. Dense nerve net cells are also present in the epidermis in the cap. They form a large ring-like structure above the radial canal commonly presented in cnidarians. Immortal jellyfish also has a bottom-living polyp form, or hydroid, which consists of stolons (external skeleton )that run along the substrate and upright branches with feeding polyps that can produce medusa buds. These polyps develop over a few days into tiny 1 mm jelly fishes, which are liberated and swim free from the parent hydroid colony.

Reproduction and lifecycle

The eggs develops in gonads of female jellyfish, which are located in the walls of the manubrium (stomach). Mature eggs are presumably spawned and fertilized in the sea by sperm produced and released by male jellyfish. Fertilized eggs develop into planula larvae, which settle onto the sea-floor (or even the rich marine communities that live on floating docks), and develop into polyp colonies (hydroids).

Lifecycle of an immortal jellyfish

The hydroids bud new jellyfishes, which are released at about one millimetre in size and then grow and feed in the plankton, becoming sexually mature after a few weeks (the exact duration depends on the ocean temperature; at 20 °C (68 °F) it is 25 to 30 days and at 22 °C (72 °F) it is 18 to 22 days). The immortal jellyfish are able to survive between 14 °C and 25 °C.

Immortality or factor of infinite lifespan 

Experiments have revealed that all stages of the medusa (jellyfish), from newly released to fully mature individuals, can transform back into polyps under the conditions of starvation, sudden temperature change, reduction of salinity and artificial damage of the bell with forceps or scissors. The transforming medusa is characterized first by deterioration of the bell, mesoglea, and tentacles. All immature medusa (with 12 tentacles at most) then turned into a cyst-like stage and then transformed into stolons and polyps.

However, about 20%-40% of mature medusa went into the stolons and polyps stage without passing the cyst-like stage. Polyps were formed after 2 days since stolons had developed and fed on food. Polyps further multiply by growing additional stolons, branches and then polyps, to form colonial hydroids. In the experiment, they would eventually transform into stolons and polyps and begin their lives once again even without suffering from environment changes or injury. This ability to reverse the biotic cycle (in response to adverse conditions) is unique in the animal kingdom, and allows the jellyfish to bypass death, rendering the immortal jellyfish potentially biologically immortal. The process has not been observed in their natural habitat, in part because the process is quite rapid and field observations at the right moment are unlikely.

FAQ

Are immortal jellyfishes immortal and indestructible at the same time ?

The answer is "no". They are immortal creatures but not indestructible though. They can die by them getting eaten by the predators or due some diseases.

Facts and Summary

• Immortal jellyfishes are immortal creatures and are often considered as the only known creature to truly achieve biological immortality to this date.

• They were discovered in the Mediterranean sea in 1883 and were studied in around the time of 1990s.

• They are immortal creatures but not indestructible

• These jelly fishes are found all over the world, especially in regions with warm water.

• Their diet mostly consists of planktons, mollusks and small fish eggs.

• Like all other jellyfishes they have no brain and no heart.

• They can reproduce both sexually and asexually.

🐙🐙🐙🐙🐟🐟🐟🐟🐋🐋🐋🐋🐋🐢🐢🐢🐡🐡🐡🐡🐡🐚🐚🐚