Kingdom: Animalia Phylum: Cnidaria Class: Hydrozoa Order: Anthomedusae Family: Oceanidae Genus: Turritopsis Species: Turritopsis nutricula Common Name: the immortal jellyfish
In the past I have made a post about lobsters, regarding the fact that they may hold the key to immortality. Today's post is also about another animal, the Turritopsis nutricula jellyfish that might also hold the secret to immortality, but instead of just not showing symptoms of aging like lobsters do, it employs another tactic to fight the passing of time.
What it actually does is reverting back to its polyp stage after having reached sexual maturity. This is actually the equivalent of a human becoming an embryo!
Turritopsis nutricula Description
The Turritopsis nutricula's polyp stage (also known as hydroid) lives in the sea bottom. The polyp in reality is a colony consisting of many stolons which run along the substrate along with upright branches. These polyps can produce many medusa buds that after a few days into very small medusae. These medusae have a size of about 1 mm and after their development they are freed from the parent hydroid colony into the ocean. Please visit this site to have a visual idea of their of this process by looking the diagrams that it provides!
The medusa stage of T.nutricula has a bell-like shape, with the maximum possible diameter being 4.5 millimetres (about 0.2 inches). The bell is almost as tall as its width. Their stomachs are quite large compared to their bodies and have a bright red colour with a cruciform-like shape in cross section.
The young medusae when released from the colony have eight tentacles that are evenly spaced out, however once adulthood is reached they typically have 80-90 tentacles.
Turritopsis nutricula life cycle and their potential immortality
T. nutricula females produce their eggs by an organ named gonad. Gonads are located inside their manubrium (stomach) walls. Although it is not yet confirmed scientists presume that once the eggs mature they are spawned and then fertilized by sperm that is released by T. nutricula males. These eggs then develop into planula larvae that settle on the ocean's bottom. The planula larvae then develops into polyp colonies, known as hydroids. As mentioned before the polyp has the ability to release many new medusa buds that develop into tiny jellies. These jellies reach sexual maturity after a few weeks. This specific time period greatly depends on the sea's temperature. For instance, sexual maturity is reached:
In 25 to 30 days if the ocean's average temperature is 20 °C (68 °F)
In 18 to 22 days if the ocean's average temperature is 22 °C (72 °F)
Each jellyfish species has an average life span that can be anything from a few hours up to many months. But the Turritopsis nutricula has found a way to defeat time and possibly live forever under perfect conditions. This is achieved with a transformation process known as transdifferentiation that allows it to revert back to its polyp stage. This process requires specific cell types found in:
The bell surface
The circulatory canal system
Once the transdifferentiation process has initiated the umbrella starts to revert itself and then the tentacles and mesoglea get re-sorbed. The now reverted jellyfish then attaches itself to the substrate by the end which was at the opposite end of the umbrella and begins to give rise to new polyps which will form a new colony. In theory , this transdifferentiation process can last on forever, effectively rendering the Turritopsis nutricula immortal. Please note that this process has never been observed in nature, however this is probably due to the fact that the process is extremely quick and as a result observing as it happens is quite difficult. During a recent laboratory experiment 100% of the individuals managed to revert back to their. Polyp stage
Currently no other species in the animal kingdom has shown the ability to reverse their life cycle. Despite the fact that this reverse-cycle trait does allow the T.nutricula to bypass death due to age related means, it hardly protects it against other potential death inflicting causes including being eaten or dyeing from a disease.
Turritopsis nutricula Habitat
Currently the T. nutricula can be found in many places (with their numbers increasingly rising) all over the world, however it is believed that its origins are from the Caribbean Sea. This jellyfish lives in temperate to tropical regions in all oceans. Scientists believe that modern ships transfer it from place to place as they discharge ballast water in ports
Turritopsis nutricula Diet T. nutricula feeds on microscopic plankton and zooplankton
Post time 8-3-2012 08:57 PM
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