Daishi Naruse, Japan
Info
Turritopsis nutricula is a very small but very special jellyfish.
The life cycle of this jellyfish is similar to many other hydrozoans, but the differences in its medusa stage make it unique.
Hydrozoans, which belong to the phylum Cnidaria, have several stages in their life cycle, usually beginning their lives as larvae that then develop into polyps that are small and cylindrical in shape.
These polyps then bud other polyps through asexual reproduction and form colonies. Once the polyps reach sexual maturity, they bud medusae from which gametes are formed.
Medusae resemble a typical jellyfish with an umbrella-like dome from which several tentacles protrude.
After medusae produce gametes several times, they die, but Turritopsis nutricula has evolved a unique adaptation that protects it from death.
Turritopsis nutricula is unique because it is able to return to an earlier stage of its life cycle by reactivating specific genes that were used only for that stage.
This reverse metamorphosis is caused by a series of cellular processes such as transdifferentiation and apoptosis.
Reversal of ontogeny has been observed in several cnidarians, but always before maturation and sexual reproduction can occur.
Turritopsis nutricula is the only organism capable of reversing ontogeny even after sexual reproduction.
In addition, the jellyfish has the rare ability to be potentially immortal in its solitary state, the medusa.
Many colonial organisms have a potentially indefinite lifespan because even if individual organisms die within the colony, the group as a whole lives on.
All stages of a medusa have the ability to revert to an outgrowth or polyp, giving them a potentially indefinite life span.
Turritopsis nutricula colonies are erect, 3 - 4 cm tall, bushy, branched and scattered, their stems are tufted, covered with a fine perisarc.
The branches are connected to the stem for a short distance before branching further.
The adult medusa is deeply bell-shaped, 1 - 2 cm wide, the abdomen is cruciform, surrounded by four large gonads, the mouth consists of four elongated lobes. The edge of the bell is provided with up to 100 tentacles.
Color: The perisarc of the colony is brownish, the hydranths are pinkish, the tentacles are white.
The bell of the medusa is transparent, the gonads are pinkish red.
Synonyms:
Corydendrium nutricula (McCrady, 1857)
Modeeria multitentaculata Fewkes, 1881
The life cycle of this jellyfish is similar to many other hydrozoans, but the differences in its medusa stage make it unique.
Hydrozoans, which belong to the phylum Cnidaria, have several stages in their life cycle, usually beginning their lives as larvae that then develop into polyps that are small and cylindrical in shape.
These polyps then bud other polyps through asexual reproduction and form colonies. Once the polyps reach sexual maturity, they bud medusae from which gametes are formed.
Medusae resemble a typical jellyfish with an umbrella-like dome from which several tentacles protrude.
After medusae produce gametes several times, they die, but Turritopsis nutricula has evolved a unique adaptation that protects it from death.
Turritopsis nutricula is unique because it is able to return to an earlier stage of its life cycle by reactivating specific genes that were used only for that stage.
This reverse metamorphosis is caused by a series of cellular processes such as transdifferentiation and apoptosis.
Reversal of ontogeny has been observed in several cnidarians, but always before maturation and sexual reproduction can occur.
Turritopsis nutricula is the only organism capable of reversing ontogeny even after sexual reproduction.
In addition, the jellyfish has the rare ability to be potentially immortal in its solitary state, the medusa.
Many colonial organisms have a potentially indefinite lifespan because even if individual organisms die within the colony, the group as a whole lives on.
All stages of a medusa have the ability to revert to an outgrowth or polyp, giving them a potentially indefinite life span.
Turritopsis nutricula colonies are erect, 3 - 4 cm tall, bushy, branched and scattered, their stems are tufted, covered with a fine perisarc.
The branches are connected to the stem for a short distance before branching further.
The adult medusa is deeply bell-shaped, 1 - 2 cm wide, the abdomen is cruciform, surrounded by four large gonads, the mouth consists of four elongated lobes. The edge of the bell is provided with up to 100 tentacles.
Color: The perisarc of the colony is brownish, the hydranths are pinkish, the tentacles are white.
The bell of the medusa is transparent, the gonads are pinkish red.
Synonyms:
Corydendrium nutricula (McCrady, 1857)
Modeeria multitentaculata Fewkes, 1881
