Most jellyfish species have a similar life cycle. 'They have eggs and sperm and these get released to be fertilised, and then you have a free-swimming larval form.The larva will travel around in the stream until it finds a hard surface on which to settle. Then it will begin to mature and grow. Larvae develop into polyps, which then branch off and mature into young jellyfish.
A mature jellyfish is referred to as a medusa. Jellyfish are members of the Cnidaria group, which also includes sea anemones and corals. They are subject to the cycle of life and death as animals, though one species is known to defy the norms.
Turritopsis dohrnii, a hydrozoan approximately 4.5 millimetres broad and tall (smaller than the nail on your little finger), may really reverse its life cycle. It has earned the moniker "immortal jellyfish." When this species' medusa is physically harmed or subjected to pressures such as famine, it shrinks in on itself, reabsorbing its tentacles and losing its ability to swim. It eventually settles as a blob-like cyst on the seafloor.
This blob evolves into a new polyp (the jellyfish's previous life stage) over the next 24-36 hours, and after maturity, medusae bud off. This phenomena has been compared to a butterfly that, instead of dying, can turn back into a caterpillar and subsequently metamorphosis into an adult butterfly.
Transdifferentiation is the process by which the jellyfish undergoes its astonishing transition, and it is highly unusual.Medusa cells and polyp cells are distinct; some cells and organs are found exclusively in polyps, while others are found only in adult jellyfish.
Transdifferentiation reprogrammes the medusa's specialised cells to become specialised polyp cells, allowing the jellyfish to regrow in a completely different body plan than the free-swimming jellyfish they were previously. They can then grow normally, creating new, genetically identical medusae.
This life cycle reversal is repeatable, and under ideal conditions, these jellyfish may never die of old age.'We may be distracted by much larger jellyfish, but tiny details like these can enlighten so much of our science about these species.
Where Can You Find Immortal Jellyfish?
Although immortal jellyfish are supposed to have originated in the Mediterranean Sea, they may now be found in waters all over the world. This recently discovered invasion is assumed to have been primarily triggered by humans.According to popular belief, ships are responsible for disseminating the organisms throughout the world's oceans. After all, the jellyfish's immortality makes it an ideal hitchhiker.
To ensure stability, ballast water is pumped in and out of vessels such as cargo ships and cruise ships. It is very likely that immortal jellyfish are brought in with this water and survive ocean crossings due to their capacity to reverse their life cycle when stressed, such as a lack of food.
According to T.dohrnii Researchers discovered that immortal jellyfish in tropical places like Panama have only eight tentacles, whereas those in temperate environments like the Mediterranean and Japan can have 24 or more. It is not yet apparent why they differ.
Another reason the eternal jellyfish's expansion may have gone ignored for so long is that they have no discernible negative consequence. Invasive species can be a concern, and some, such as zebra mussels in North America, cause havoc that is extremely expensive to repair. Others, such as hippos introduced to Colombia around 30 years ago, represent a threat to the native animals with which they coexist.
While there haven't been any serious difficulties associated to eternal jellyfish, their silent proliferation at the hands of humans is yet another good reminder of our influence on the natural world, even when we don't realise it.
Who Discovered the Immortal Jellyfish?
The genus T. Scientists first described dohrnii in 1883. Their immortality was discovered accidentally 100 years later, in the 1980s.Christian Sommer and Giorgio Bavestrello, students, gathered Turritopsis polyps and preserved them until medusae were released. The jellyfish were expected to develop before spawning and producing larvae, but when the jar was checked again, they were shocked to find several newly settled polyps.
They kept watching the jellyfish and discovered that when they were stressed, the medusae would descend to the bottom of the jar and turn into polyps without fertilisation or the traditional larval stage. The finding attracted the world's attention, boosted by the amazing appellation "immortal jellyfish."
Can Immortal Jellyfish Really Live Forever ?
T. Dohrnii may break the rules in order to revitalise itself, but it cannot always avoid death. Jellyfish, even eternal jellyfish, are prey to other animals such as fish and turtles. Polyps are also vulnerable to predation from creatures such as sea slugs and crustaceans. Knowing how long jellyfish, such as T. Can live for dohrnii can be difficult.
A lot of deep-ocean science takes a long period, and it is quite expensive to make observations over time to see change. The jellyfish must also be kept in optimal conditions where they will not be harmed by anything external, such as humans or other predators.'
T. dohrnii is sensitive, making it difficult to keep in a lab for research. Despite the difficulties, one scientist has had long-term success using captive immortal jellyfish.
Since the 1990s, Japanese scientist Shin Kubota has kept populations of immortal jellyfish looping through their peculiar back and forth life cycle. Kubota's work with the species is time-consuming, since he must monitor and care for the colonies on a regular basis, including slicing up their minuscule meals of brine shrimp eggs under a microscope so the tiny jellyfish can consume them.
However, Kubota has observed that over a two-year period, captive colonies of the jellyfish organically renewed themselves up to ten times, often at intervals of only a few days.
Written By: Greeshma Chowdary
Edited By: Nidhi Jha
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