December252012
The white one (by jyotsna_)

The white one (by jyotsna_)

November112012
Turritopsis nutricula, the immortal jellyfish, is a hydrozoan whose medusa, or jellyfish, form can revert to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage.  It does this through the cell development process of transdifferentiation. Cell transdifferentiation is when the jellyfish “alters the differentiated state of the cell and transforms it into a new cell”. In this process the medusa of the immortal jellyfish is transformed into the polyps of a new polyp colony. First, the umbrella reverts itself and then the tentacles and mesoglea get resorbed. The reverted medusa then attaches itself to the substrate by the end that had been at the opposite end of the umbrella and starts giving rise to new polyps to form the new colony.
Theoretically, this process can go on indefinitely, effectively rendering the jellyfish biologically immortal, although in nature, most Turritopsis, like other medusae, are likely to succumb to predation or disease in the plankton stage, without reverting to the polyp form.
No single specimen has been observed for any extended period, so it is not currently possible to estimate the age of an individual, and so even if this species has the potential for immortality, there is no laboratory evidence of many generations surviving from any individual. (via Turritopsis nutricula - Wikipedia, the free encyclopedia)

Turritopsis nutricula, the immortal jellyfish, is a hydrozoan whose medusa, or jellyfish, form can revert to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage.  It does this through the cell development process of transdifferentiation. Cell transdifferentiation is when the jellyfish “alters the differentiated state of the cell and transforms it into a new cell”. In this process the medusa of the immortal jellyfish is transformed into the polyps of a new polyp colony. First, the umbrella reverts itself and then the tentacles and mesoglea get resorbed. The reverted medusa then attaches itself to the substrate by the end that had been at the opposite end of the umbrella and starts giving rise to new polyps to form the new colony.

Theoretically, this process can go on indefinitely, effectively rendering the jellyfish biologically immortal, although in nature, most Turritopsis, like other medusae, are likely to succumb to predation or disease in the plankton stage, without reverting to the polyp form.

No single specimen has been observed for any extended period, so it is not currently possible to estimate the age of an individual, and so even if this species has the potential for immortality, there is no laboratory evidence of many generations surviving from any individual. (via Turritopsis nutricula - Wikipedia, the free encyclopedia)

August232012
shedsumlight:

Cyanea capillata - world’s largest jellyfish.
Image: Alexander Semenov

shedsumlight:

Cyanea capillata - world’s largest jellyfish.

Image: Alexander Semenov

(via scientificthought)

August162012
Full Sail — Jellyfish

by PAAT

Full Sail — Jellyfish

by PAAT

August132012
Moon jellyfish: fewer jellyfish have been spotted in UK waters this year although recent warmer weather could bring out more blooms of the sea creatures, conservationists say. While sightings are down in the UK, visitors to Spain’s Costa del Sol have been warned of massive blooms of mauve stinger jellyfish which have left many people requiring treatment.

Moon jellyfish: fewer jellyfish have been spotted in UK waters this year although recent warmer weather could bring out more blooms of the sea creatures, conservationists say. While sightings are down in the UK, visitors to Spain’s Costa del Sol have been warned of massive blooms of mauve stinger jellyfish which have left many people requiring treatment.

July32012
The black sea nettle (Chrysaora achlyos), sometimes informally known as the “black jellyfish” due to its dark coloration, is a species of jellyfish that can be found in the waters of the Pacific Ocean.  It is a giant jellyfish, with its bell measuring up to 1 m (3 ft) in size, and its oral arms extending up to 6 m (20 ft) in length.  Despite its size and occasional proximity to Pacific coastal cities, the Black sea nettle was only recognized and scientifically described as a separate species in 1997. It has the scientific distinction of being the largest invertebrate discovered in the twentieth century.
The sea nettle is radially symmetrical, marine, and carnivorous. Its mouth is located at the center of one end of the body, which opens to a gastrovascular cavity that is used for digestion. It has tentacles that surround the mouth to capture food. Nettles have no excretory or respiratory organs.

The black sea nettle (Chrysaora achlyos), sometimes informally known as the “black jellyfish” due to its dark coloration, is a species of jellyfish that can be found in the waters of the Pacific Ocean.  It is a giant jellyfish, with its bell measuring up to 1 m (3 ft) in size, and its oral arms extending up to 6 m (20 ft) in length.  Despite its size and occasional proximity to Pacific coastal cities, the Black sea nettle was only recognized and scientifically described as a separate species in 1997. It has the scientific distinction of being the largest invertebrate discovered in the twentieth century.

The sea nettle is radially symmetrical, marine, and carnivorous. Its mouth is located at the center of one end of the body, which opens to a gastrovascular cavity that is used for digestion. It has tentacles that surround the mouth to capture food. Nettles have no excretory or respiratory organs.

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