#Mnemiopsis

[vestaignis]

Мнемиопсис - древнейший, люминесцентный организм.

Mnemiopsis is an ancient, luminescent organism.

Гребневики не являются медузой, даже не имеют с ними родственных связей, хотя называть их по другому не выходит. Внешне мнемиопсисы легкие, прозрачные, с юбочками-лопастями и гребными пластинами. У них нет мозга, сердца, скелета, зато есть нервная система, орган равновесия и способность к люминесценции. Мнемиопсис – хищник, это плотоядное животное питающийся зоопланктоном, икринками, личинками рыб и моллюсков. На свету переливается яркими цветами, ночью придает морским волнам желтоватое люминисцентное свечение.

По самым последним данным ученых гребневик является одним из первых живых созданий на планете Земля. Ранее считалось, что этот титул принадлежит морским губкам — гораздо более примитивным существам.

Совсем недавно Гребн­евик Мнемиопсис (Mne­miopsis leidyi) – обитал лишь по ту стор­ону океана: вдоль во­сточного побережья Северной и Южной Амер­ики, от Канады до Ар­гентины. Но, благода­ря интенсивному судо­ходству, вместе с ба­лластными водами он перебрался и в Европ­у. Как оказалось, гр­ебневик может приспо­сабливаться к большо­му диапазону солёнос­ти. Теперь его ареал обитания включает Чёрное море, Азовское, Эгейское и Мраморн­ое моря, западное по­бережье Швеции, даже почти пресное Балти­йское море .

Ctenophores are not jellyfish, and they are not even related to them, although it is impossible to call them anything else. Externally, Mnemiopsis are light, transparent, with blade-like skirts and paddle plates. They do not have a brain, heart, or skeleton, but they do have a nervous system, an organ of balance, and the ability to luminesce. Mnemiopsis is a predator, a carnivore that feeds on zooplankton, eggs, and larvae of fish and mollusks. In the light it shimmers with bright colors, at night it gives the sea waves a yellowish luminescent glow.

According to the latest data from scientists, the ctenophore is one of the first living creatures on planet Earth. Previously it was believed that this title belongs to sea sponges - much more primitive creatures. More recently, the Ctenophore Mnemiopsis (Mnemiopsis leidyi) lived only on the other side of the ocean: along the eastern coast of North and South America, from Canada to Argentina. But, thanks to intensive shipping, it moved to Europe along with ballast waters. As it turns out, the ctenophore can adapt to a wide range of salinity. Now its habitat includes the Black Sea, the Azov, Aegean and Marmara Seas, the western coast of Sweden, even the almost fresh Baltic Sea.

Источник: telegram Океан,

nplus1.ru/news/2020/05/08/mnemiopsis,

/www.nkj.ru/archive/articles/23340/, /pikabu.ru/story/mnemiopsis__chuma_xxi_veka_4346622,/turizm.pibig.info/19015-grebnevik-v-chernom-more-mnemiopsis.html,

/ezoteriker.ru/grebnevik-beroe-v-chernom-more-mnemiopsis-chuma-hhi-veka-9-foto-mnemiopsis/,

//spadilo.ru/grebneviki-meduzy-ili-polipy/,

/dzen.ru/a/YbGQswZ7Y0VAg-7O,

/myanapa.ru/fauna/invertebrates/grebnevik/,

//seaforum.aqualogo.ru/topic/54177-гребневик-мнемиопсис-mnemiopsis-leidyi/.

[ifelten]

Amerikansk ribbegople / Dræbergople (Mnemiopsis leidyi)

Sea Walnut aka Warty Comb Jelly (Mnemiopsis leidyi)

[todropscience]

TWO INJURED SEA COMBS CAN FUSE INTO A SINGLE ENTITY, AND THRIVE

In a surprising new discovery, scientists have found that two injured individuals of Mnemiopsis leidyi, a species of comb jellies or ctenophores, can fuse into a single entity. This phenomenon, which challenges our typical understanding of biological processes, reveals just how remarkable these planktonic creatures truly are.

Ctenophores, known for their translucent beauty and delicate movement in the ocean, appear to lack a mechanism called allorecognition—the ability to distinguish between self and non-self. This means that, when two comb jellies are injured and placed close together, they can merge, not just physically, but also functionally. Their nervous systems combine, allowing them to share nerve signals (or action potentials), and even their digestive systems become one.

The discovery was made by Dr. Jokura and his team, who were observing comb jellies in a seawater tank. After removing parts of their lobes and placing them side by side, they were astonished to see 9 out of 10 injured comb jellies fuse to form a single organism. Even more fascinating, the newly formed organism survived for at least three weeks, with its muscle contractions fully synchronized within just two hours. The digestive system also fused, enabling food taken in by one mouth to travel through their shared canal and exit through both anuses—although not at the same time!

While the exact benefits of this fusion are still unclear, the researchers believe that studying this phenomenon could provide valuable insights into how organisms integrate nervous systems and even how tissue regeneration occurs. It may also offer clues about immune system functions in species where the lines between individual organisms become blurred.

This discovery offers a glimpse into the hidden potential of the ocean’s lesser-known inhabitants, challenging what we think we know about biological boundaries and cooperation.

Video: Kei Jokura

Reference: Jakura et al., 2024. Rapid physiological integration of fused ctenophores. Current Biology

[mindblowingscience]

When things get tough in adulthood, it might seem appealing to return to simpler times. One bizarre marine creature has taken this approach to dire situations quite literally, regressing its physical adult body to a juvenile stage once the stress of starvation or injury has subsided. Until now, the immortal jellyfish (Turritopsis dohrnii) was the only species thought to be able to wind back the clock on jelly-puberty like this, but now it's joined by Mnemiopsis leidyi, better known as the sea walnut or the warty comb jelly.

Contiue Reading.

[royalchewy]

Pre-work art, because my brain only wants to think of comb jellies. We have my techno OC, Leidyi (who is missing most of her fun details) with Mnemiopsis leidyi, the comb jelly species she was inspired by. A better version to made who knows when, if ever

[harrelltut]

The ctenophore Mnemiopsis leidyi (sea walnut) in our laboratory in Bergen, Norway.

[laurelnose]

These are not even close to being deep-sea creatures? Mnemiopsis leidyi is a shallow-water coastal comb jelly—a famously shallow-water comb jelly, in fact, owing to their being virulently invasive across Europe and Asia due to being common ballast water hitchhikers. They’re native to the western Atlantic and can be found up and down the Americas, including the notoriously not-very-deep Chesapeake Bay. Which is why you can easily put them in petri dishes and bother them with pipettes for gifs, lmao.

Interesting news for fucked up weirdos who enjoy body horror and exploring differences between Self and Other

[dropsofsciencenews]

Reconocerse en el otro… ¡Literalmente!

¿Alguna vez has observado algo y de repente notaste un detalle que no encaja? A veces, este tipo de sorpresa puede llevar a un descubrimiento increíble, especialmente si estás observando un tanque lleno de ctenóforos.

Pero, ¿qué son los ctenóforos? Son organismos marinos transparentes, delicados y hermafroditas que se reproducen sexualmente. Viven principalmente en mar abierto y son conocidos por su belleza luminosa y bandas iridiscentes. El nombre "Ctenophora" proviene del griego "ktenos" (peine) y "phoros" (portador), refiriéndose a los característicos cilios en forma de peine que utilizan para moverse. Aunque a menudo se les confunde con las medusas, pertenecen a un filo diferente.

Ahora imagina estar en un laboratorio, frente a un tanque lleno de Mnemiopsis leidyi, conocida también como la nuez de mar, una de las especies invasoras de ctenóforos más notorias del mundo. Esta especie puede comer hasta diez veces su peso corporal al día, matando de hambre a ecosistemas enteros al devorar todo lo que está en la base de la cadena alimentaria. Mientras observas detenidamente, algo llama tu atención: un individuo inusualmente grande con dos extremos posteriores y dos órganos apicales en lugar de uno. No, no estás viendo doble, es un solo ctenóforo. Esta peculiar observación llevó a un grupo de científicos japoneses a hacerse una pregunta: ¿es posible que estos ctenóforos, probablemente heridos durante la recolección, hayan fusionado sus cuerpos durante la curación, aprovechando el espacio limitado en el tanque?

Para responder a esta pregunta, los científicos decidieron probar su hipótesis con un experimento. Removieron parcialmente los lóbulos de otros individuos, colocándolos en estrecho contacto y fijándolos en platos de disección. ¿El resultado? En nueve de cada diez casos, las lesiones se fusionaron durante la noche, creando un tejido continuo. Estos animales fusionados lograron sobrevivir al menos tres semanas.

Pero el descubrimiento no termina aquí. Después de una sola noche, los dos individuos originales se habían convertido en uno solo, sin signos visibles de separación. Cuando los investigadores estimularon un lóbulo, todo el cuerpo fusionado reaccionó con una contracción sincronizada. Además, ¡sus sistemas digestivos también se habían fusionado! Cuando una de las bocas ingería comida coloreada con fluorescencia, se podían observar las partículas pasar a través del canal fusionado y ser expulsadas por ambos orificios anales, aunque no de manera simultánea.

Estos resultados demuestran no solo el comportamiento único de estos extraordinarios animales, sino también sugieren que M. leidyi podría carecer de alorreconocimiento—la capacidad de distinguir entre uno mismo y los demás—un mecanismo que previene la fusión entre individuos de la misma especie. En los seres humanos, esta capacidad es lo que causa el rechazo de los órganos trasplantados. Los ctenóforos se encuentran entre los grupos de animales más antiguos entre los metazoos actuales, poseen un sistema nervioso único, y su falta de alorreconocimiento podría ayudarnos a entender mejor cuándo evolucionó este mecanismo en los animales.

¡Hasta pronto y buena ciencia!

fuente

[rayhaber]

Taraklıların Şaşırtıcı Kaynaşma Özellikleri

Taraklıların Şaşırtıcı Özellikleri Denizanasına benzeseler de, onların çok uzak akrabası olan taraklılar (Ctenophores), boyutları birkaç milimetre ile 1,5 metre arasında değişen ilginç deniz canlılarıdır. 700 milyon yıl önce evrilen bu canlıların, günümüzde hâlâ hayatta olan en eski hayvan grubu olduğu tahmin edilmektedir. Özellikle bu şubedeki Mnemiopsis leidyi türleri, kendini yenileme…

[noncompliantcyborg]

I've really not been keeping up with my plan of sharing a print a day for January but here's some ctenophores in space!

Note on image credit: The background image is modified from a public domain image taken with the Hubble Space Telescope with credit to NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team. The ctenophores are all photos by me and I created the edit.

[bpod-bpod]

Tough Nut

While humans have to make do with love, abstract maths and making a decent lasagne, there are creatures on Earth capable of other enviable feats. Axolotl can regenerate most of their organs after injury, and researchers find this ‘sea walnut’ (Mnemiopsis leidyi), to be biologically immortal. After a period of severe stress or injury, M. leidyi undergoes ‘reverse development’, shrinking and resetting some of its tissues to an earlier developmental stage to better repair and recover. This incredible behaviour has parallels with certain jellyfish species such as Turritopsis dohrnii, but there may be lessons here for mammals too. While it’s unlikely we’ll be immortal any time soon, M. leidyi could be used as a model organism for studying the molecular details of ageing and rejuvenation – perhaps helping us to heal faster from injury, if not from the ravages of age.

Written by John Ankers

Video from work by Joan J. Soto-Angel and Pawel Burkhardt

Michael Sars Centre, University of Bergen, Bergen, Norway

Video originally published with a Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)

Published in Proceedings of the National Academy of Science (PNAS), October 2024

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[sarahmackattack]

Every single one of these animals was found by me with almost no equipment along the jersey shore (just a fishing rod for the fish and a pint glass at most for everything else).

In order of appearance:

Horseshoe crab

Sea walnut (Mnemiopsis leidyi)

Mantis shrimp

Sea angel (clione)

Black Sea Bass

Spider crab

Sea gooseberry (Pleurobrachia pileus)

Unidentified crustacean larva

ghost crab

Want to learn more about the shore? Text SHORE to 1-833-SCI-TEXT

[invincibleworld]

Some of you may be familiar with model organisms in biology but even so, you may think about mice, rabbits or flies rather than ctenophores. The whole purpose of having a model organism is to be able to understand particular biological functions/processes by using an organism that can be maintained easily, has a relatively short generation time and has its genome sequenced (this allows us to really understand their genetic makeup). Since this species of ctenophore (Mnemiopsis leidyi) has had its genome sequenced it allows us to identify key genes/proteins and try to determine their function.

The work I am currently doing for my project is focused on understanding the origin of the nervous system.

There's been a long standing debate amongst scientists over which species of animal first diverged from all other metazoans whether it be sponges or ctenophores. For a long time it has been thought that sponges are the sister group to all metazoans, although more recently studies have suggested that ctenophores are. Sponges are really simple animals that lack nervous systems, whereas ctenophores are more complex and have a nervous system. If ctenophores are then in fact found to be the sister group to all other metazoans, it poses the questions about whether the complex structures such as neurons and synapses evolved once or multiple times independently?

If you check you can see a diagram showing what I mean by the "sister group" to all metazoans. The first pic identifies sponges as the sister group, but with more analysis on a molecular basis, the 3rd pic could be possible.

Since most of the studies on neurons and nervous systems more generally are focused on metazoans, the work at this lab uses ctenophores to understand more about their complex biology with the aim of understanding the origins of neurons.

[cosmicanger]

For the first time, researchers were able to fuse the bodies of injured warty comb jellies (Mnemiopsis leidyi). The team discovered the creatures' incredible ability by accident. (This photo shows a single individual in the wild.) (Image credit: Alamy)

[sirsparklepants]

So. I thought none of the creatures I have tattooed on me are actually to scale, I simply had my artist do a size that looks good. However, I went and looked them up and. My pelican eel is about 30in long. My chambered nautilus is 6in in diameter. And my comb jelly (it's a generic lobate but looks most like Mnemiopsis) is 4 inches long. And those are all. In about the correct range. I'm laughing SO HARD this was not at all intentional.

[royalchewy]

Day 10: Techno Trolls

Leidyi was named after the comb jelly (which is NOT a jellyfish btw) called Mnemiopsis leidyi. They are also referred to as the warty comb jelly and sea walnuts. This is her observing the very animal she was named after (and what I used as inspiration for her design).

Here’s a recent article about a recent thing with the species, if anyone is curious. They’re very interesting, so pretty to look at, and pretty invasive in some seas (which is how I got interested in them in the first place).