"The history of the genus Atolla is typical, for the bathypelagic group of medusae, for as one deep sea expedition after another brought battered specimens to light, nine species, supposedly distinct, were proposed. But as greater numbers of specimens were studied, the number of these species was successively reduced, until it now seems likely, says Browne (1916), that all the Atollas which have yet been seen, represent variants, or contraction-phases, of two species only; A. wyvillei (the earliest named), with smooth lappets, and A. chuni, in which each of the lappets is studded with 7-9 small papillae.4 Even the sculpturing of the central lens; whether with or without radial furrows at its margin, with the degree of development and exact confirmation of these when present, is found, by Browne (1916), to be less reliable as a systematic character than previously supposed. And this conclusion is supported by the present series, which shows intermediates between the bairdii type, with smooth central lens; the verrillii type in which the lens is scored with narrow radial furrows; and the wyvillei type where at least the edge of the lens is indented with broad radial notches though its central portion may be smooth.
This character, then, goes into the same discard with most of the others which have been used to separate "species" of Atolla; relative breadth of the septal nodes for example, and the number of antimeres.
It was long ago observed (Fewkes 1886; Maas 1897) that Atollas, when taken, or after preservation, show a smooth zone between ring furrow and tentacular pedalia, which is not visible on surface views of other specimens. This difference, according to Vanhöffen (1902) represents merely a contraction- or compression-phase, for none of the Valdivia specimens of Atolla lacked this zone intermediate between coronal furrow and padalia, though in some it was concealed by the everhanging margin of the central lens. Mayer (1910) has, however proposed the presence or absence of this zone anew, as a specific character, dividing the Atollas with smooth lappets into bairdii with it: and wyvillei lacking it. This supposed difference has not been discussed by writers, and therefore demands a word of comment here.
No special attention was payed to this character in my study of the Albatross Atollas from the Eastern Tropical and Northwestern Pacific, beyond the fact that in most of them this zone was concealed (Bigelow 1909, Pl. 9, Fig. 3, Pl. 10, Fig. 9). Reexamination of some of these specimens gives the following results—Out of 8 specimens, in fair condition, from off Japan ('Eastern Sea,' Alba-1ross Station 4907), 30-65 mm. in diameter, seven have the central lens overhanging, and nearly entirely concealing the anular zone, while in one specimen the central lens is much more elevated, leaving the edge of this zone visible, in aboral view.
Two out of three excellent specimens from Bering Sea, Albatross Station 4766, with disc very flat and firm, show no distinct intermediate zone, in aboral view, their pedalia seemingly separated from the margin of the central lens only by the coronal furrow. The third, in equally good state, shows an intermediate zone much narrower than the length of the tentacular pedalia.
As a radial section though the bell of this last specimen shows, the coronal furrow is very deep when this intermediate zone is nearly or quite concealed: deeper, in this case than the length of the tentacular pedalia. And the connecting zone below it, between central lens and peripheral zone, is narrow. Another much flattened specimen, also from Bering Sea (Albatorss Station 4773), about 35 mm. in diameter, also has the central lens practically in contact with the pedalia. And among the Atollas which I have examined such has been the condition in general, in the specimens in which the gelatinous substance was firmest, the bells flattest, and the pigment most nearly intact after preservation, i.e. in those that were probably alive when placed in the preservative, and so may be supposed to have suffered muscular contraction. This same state is shown by Vanhöffen (1902, p. 5, Fig. 24).
Two other specimens from this same station, respectively of 35 and 45 mm., with the central part of the disc more elevated, and the gelatinous substance softer, show intermediate zones between ring furrow and pedalia, nearly as wide as the latter.
The great majority of the large Arcturus specimens, listed below, illustrate a still more relaxed state, with the whole medusa softer and more cup shaped, the central lens bulging higher above the level of the ring furrow, the marginal zone hanging downward, and the smooth intermediate zone about as broad as the tentacular pedalia are long: in some cases even broader.
Radial sections of specimens of this type show the basal connecting zone at the bottom of the coronal furrow, between periphery (corona) and central disc, relatively thicker (1/3 to 1/2 as thick as the coronal furrow is deep) than is the case when the smooth annular zone is less prominent; furthermore, in such specimens the relaxed annular zone is much softer in texture than the pedal zone.
As has long been known, this connecting zone is the site of a circumferential strand of contractile fibres; and complex series of such fibres are imbedded in the gelatinous substance of Atolla.
In short, the apparent presence or absence of the smooth annular zone, has no genetic significance in Atolla. Every gradation is to be found (among specimens in different state of contraction or relaxation) from those in which no such band can be distinguished, other than the smooth outer wall of the coronal furrow, to others showing a protruberant band of this sort, as broad as the pedalia are long and which may or may not be marked off from the latter by a furrow.
Such differences do not indicate the existence of varieties, but reflect nothing more than the state of the animal—whether still alive, or dead and flaccid—when placed in the preservative, or the amount of muscular contraction it may have experienced, in the latter."
(Bigelow, 1928)
Atolla wyvillei, also known as the Atolla jellyfish or Coronate medusa, is a species of deep-sea crown jellyfish (Scyphozoa: Coronatae).[2] It lives in oceans around the world.[3] Like many species of mid-water animals, it is deep red in color. This species was named in honor of Sir Charles Wyville Thomson, chief scientist on the Challenger expedition.
It typically has 20 marginal tentacles and one hypertrophied tentacle which is larger than the rest.[4] This long trailing tentacle is thought to facilitate prey capture.[5]
This species is bioluminescent.[6] When attacked, it will launch a series of flashes, whose function is to draw predators who will be more interested in the attacker than itself. This has earned the animal the nickname "alarm jellyfish".[7]
Marine biologist Edith Widder created a device based on the Atolla jellyfish's distress flashes called the E-jelly, which has been used successfully and efficiently to lure in mysterious and rarely seen deep-sea animals for filming and documentation. The device's mimicry of the live animal was such that it successfully lured in a giant squid in an expedition financed by Discovery Channel and NHK to find the creature.[8]
The body of Atolla wyvillei has a bell shape, of around 20–174 mm (0.79–6.85 in) in diameter, and is rimmed by several moderately long tentacles, including a single, long, hypertrophied tentacle, which has several purposes, including aid in predation as well as aid in reproduction. These jellyfish do not have a digestive system, a respiratory system, a circulatory system, or a central nervous system.
Atolla wyvillei is found all over the globe in the deep ocean. There has been evidence of them found in The deep ocean in a depth from 1,000 to 4,000 m (3,300 to 13,100 ft), an area commonly called the “Midnight Zone” (Unknown, 2013).
Atolla wyvillei can reproduce in two different ways. They can reproduce asexually like many other jellyfish species. This process involves the development into polyps that then produce buds that grow into larvae. Atolla wyvillei can also reproduce sexually. They attach themselves to another Atolla wyvillei by grabbing them with their hypertrophied tentacle and pulling themselves toward the other to mate.
Atolla wyvillei have been found to prey on crustaceans and other floating nutrients. Atolla wyvillei can trap its prey through the use of its hypertrophied tentacle. It can passively catch its prey by leaving the tentacle extended and allow it to catch things that may be floating nearby.
Bioluminescence is the production of visible light by a living organism (Herring 2004). Bioluminescence is a common phenomenon in marine animals found in the deep sea. Atolla wyvillei has adapted a safety response to avoid predation. When Atolla wyvillei is attacked it produces an array of blue light flashes. The propagation rate of these flashes are 5–50 cm/s (2.0–19.7 in/s) and they propagate in circular waves (Herring 2004). It is because of these blue flashes that Atolla wyvillei has been nicknamed the “alarm jelly”. It is believed that the purpose of these flashes is to attract a bigger predator than the one that was currently attacking it (Herring 2004). It is an attempt to scare the predator that is currently attacking it with a larger predator that could possibly prey on the predator attacking it.[9]
There has been evidence that Atolla wyvillei is threatened by shrimp (Moore, 1993). A close relative of Atolla species, the crown jellyfish is eaten as a delicacy in Japan (Seaunseen, 2014).
Atolla wyvillei, also known as the Atolla jellyfish or Coronate medusa, is a species of deep-sea crown jellyfish (Scyphozoa: Coronatae). It lives in oceans around the world. Like many species of mid-water animals, it is deep red in color. This species was named in honor of Sir Charles Wyville Thomson, chief scientist on the Challenger expedition.
It typically has 20 marginal tentacles and one hypertrophied tentacle which is larger than the rest. This long trailing tentacle is thought to facilitate prey capture.
This species is bioluminescent. When attacked, it will launch a series of flashes, whose function is to draw predators who will be more interested in the attacker than itself. This has earned the animal the nickname "alarm jellyfish".
Marine biologist Edith Widder created a device based on the Atolla jellyfish's distress flashes called the E-jelly, which has been used successfully and efficiently to lure in mysterious and rarely seen deep-sea animals for filming and documentation. The device's mimicry of the live animal was such that it successfully lured in a giant squid in an expedition financed by Discovery Channel and NHK to find the creature.
Atolla wyvillei, aussi dénommée méduse Atolla, est une espèce de méduse des profondeurs appartenant à la famille des Atollidae[1]. On la trouve dans tous les océans du monde[2]. Comme beaucoup d'espèces vivant à ces profondeurs, elle est de couleur rouge vif. Cette espèce a été nommée en l'honneur de Sir Charles Wyville Thomson, chef de mission de l'expédition du Challenger.
Elle possède généralement 20 tentacules marginaux ainsi qu'un hypertrophié qui est plus longue que les autres[3]. On suppose qu'elle facilite la capture des proies[4].
Cette espèce est bioluminescente[5]. Lorsqu'elle est attaquée, elle produit une série de flashs dont la fonction est d'attirer les prédateurs qui seront alors plus intéressés par l'attaquant qu'à elle. Cela lui a valu le surnom de "méduse-alarme"[6].
La biologiste marin Edith Widder a créé un appareil basé sur les flashs de détresse de la méduse Atolla appelé E-jelly, qui a été utilisé avec succès et a prouvé son efficacité pour appâter des animaux des grandes profondeurs rares et difficiles à observer afin de les filmer pour des documentaires. La façon qu'a l'appareil d'imiter le comportement de l'animal a été si efficace qu'elle a permis d'attirer un calamar géant lors d'une expédition financée par Discovery Channel et NHK qui cherchait à filmer cet animal[7].
Le corps d'Atolla wyvilei a une forme de cloche et possède différents tentacules modérément longs le long de la cloche. Celle-ci fait entre 20 et 174 mm de diamètre selon l'âge et la taille du spécimen. Elle possède également un long tentacule appelé tentacule hypertrophié, qui a différentes fonctions, dont l'aide à la prédation et à la reproduction. Ces méduses n'ont ni système digestif, ni système respiratoire, ni système circulatoire, ni système nerveux central. Cela signifie qu'elle ne possède pas d'organe similaire à un cerveau.
Atolla wyvillei se retrouve dans tous les océans profonds de la planète (zone bathypélagique). Il y a eu des preuves de son existence à des profondeurs entre 1000 et 4 000 m dans ce qu'on appelle la Zone de Minuit (Midnight Zone en anglais)[8].
Atolla wyvillei peut se reproduire de deux façons différentes. Elle peut se reproduire de façon asexuée comme beaucoup d'autres espèces de méduses, ce qui implique le développement de polypes qui ensuite produisent des bourgeons qui deviennent des larves. Elle peut également se reproduire de façon sexuée car elle possède des gonades[9] ; deux individus s'attachent entre eux par leur tentacule hypertrophié et se tirent entre eux afin de copuler.
On a observé que cette méduse se nourrit de petits crustacés et d'autres nutriments planctoniques. Elle peut piéger ses proies grâce à son tentacule hypertrophié, ainsi que les attraper passivement en laissant son tentacule déployé pour attraper de la nourriture qui dérive au gré des courants dans son environnement comme du plancton.
La bioluminescence (production de lumière visible par un être vivant) est un phénomène communément retrouvé chez les animaux marins vivant dans l'océan profond. Atolla wyvillei a développé une réponse adaptative afin de se protéger des prédateurs : lorsqu'elle est attaquée, elle produit une série de flashs bleus à une vitesse de propagation de 5 à 50 cm/s qui se propagent en vagues circulaires. C'est à cause de ces flashs bleus qu'Atolla wyvillei a été surnommée la "méduse-alarme". On suppose que le but de ces flashs est d'attirer un prédateur plus gros que celui qui attaque la méduse au départ afin d'apeurer ce dernier qui pourrait être alors attaqué par un nouveau prédateur plus gros, attiré par ces flashs de lumière bleue[10].
On a trouvé des preuves qu'Atolla wyvillei est menacé par certaines crevettes[11]. De plus, un parent proche de cette méduse, de l'ordre des Coronatae, est consommée au Japon en tant que mets fin[12].
Atolla wyvillei, aussi dénommée méduse Atolla, est une espèce de méduse des profondeurs appartenant à la famille des Atollidae. On la trouve dans tous les océans du monde. Comme beaucoup d'espèces vivant à ces profondeurs, elle est de couleur rouge vif. Cette espèce a été nommée en l'honneur de Sir Charles Wyville Thomson, chef de mission de l'expédition du Challenger.
Elle possède généralement 20 tentacules marginaux ainsi qu'un hypertrophié qui est plus longue que les autres. On suppose qu'elle facilite la capture des proies.
Cette espèce est bioluminescente. Lorsqu'elle est attaquée, elle produit une série de flashs dont la fonction est d'attirer les prédateurs qui seront alors plus intéressés par l'attaquant qu'à elle. Cela lui a valu le surnom de "méduse-alarme".
La biologiste marin Edith Widder a créé un appareil basé sur les flashs de détresse de la méduse Atolla appelé E-jelly, qui a été utilisé avec succès et a prouvé son efficacité pour appâter des animaux des grandes profondeurs rares et difficiles à observer afin de les filmer pour des documentaires. La façon qu'a l'appareil d'imiter le comportement de l'animal a été si efficace qu'elle a permis d'attirer un calamar géant lors d'une expédition financée par Discovery Channel et NHK qui cherchait à filmer cet animal.
Atolla wyvillei Haeckel, 1880 è una scifomedusa di acque profonde appartenente alla famiglia Atollidae[1] che vive negli oceani di tutto il mondo. Questa specie è stata nominata in onore di Sir Charles Wyville Thomson, scienziato capo della Spedizione Challenger.
È generalmente di colore rosso scuro[2]. Generalmente ha 22 tentacoli marginali più un tentacolo ipertrofico, più lungo degli altri, il quale serve a facilitare la cattura della preda. È bioluminescente. Se attaccata, rilascia dei lampi di luce che hanno lo scopo di attirare predatori più grandi che saranno verosimilmente più interessati alla minaccia che non alla medusa stessa. Questo meccanismo di difesa le ha fatto guadagnare il nome di "medusa allarme".
Atolla wyvillei Haeckel, 1880 è una scifomedusa di acque profonde appartenente alla famiglia Atollidae che vive negli oceani di tutto il mondo. Questa specie è stata nominata in onore di Sir Charles Wyville Thomson, scienziato capo della Spedizione Challenger.
Atolla wyvillei is een schijfkwal uit de familie Atollidae. De naam Atolla wyvillei werd in 1880 voor het eerst gepubliceerd door Haeckel.
Bronnen, noten en/of referenties
[[commons:{{{commons}}}|Multimedia w Wikimedia Commons]] Atolla wyvillei, Atolla gigantea (Atolla jellyfish) – gatunek z rodziny Atollidae składającej się z jednego rodzaju Atolla. Cechą charakterystyczną dla osobników tego rodzaju jest m.in. większa liczba narządów zmysłów niż u innych krążkopławów. Pomiędzy kolejnymi ropaliami znajdują się macki. Ich parasol w części krańcowej jest pofałdowany.
Osobniki tego gatunku występują w strefach głębinowych mocno zasolonych mórz i oceanów. Zaobserwowano je w rejonach Afryki ( szczególnie Przylądek Dobrej Nadziei), Azji, Ameryki Pn. i Pd., a nawet Antarktyki.[2]
Krawędź parasola zakończona jest 44 lekko zaokrąglonymi fałdami. Przedstawiciele tego gatunku posiadają 22 krótkie czułki leżące naprzemiennie z ropaliami, na podstawach zwanych pedaliami. Jedna czułka jest wyraźnie wydłużona i służy do chwytania ofiar. Mają promienisty żołądek z licznymi kieszeniami zwiększającymi powierzchnię chłonąco-trawiącą. 8 wydłużonych gonad, zaokrąglonych na końcach. Bezbarwną mezogleę osłania czerwono-brunatna ektoderma. Gatunek ten posiada zdolność do bioluminescencji.
Średnica Atolla wyvillei wynosi 12- 150 mm.
Zdolność do bioluminescencji wykorzystywana jest przez Atolla wyvillei do zdobywania pokarmu. Dostępność światła w strefie ich występowania jest ograniczona, dlatego powstające światło powoduje, że drobne organizmy przemieszczają się ku jego źródłu. Ich pokarm stanowi przede wszystkim zawiesina organiczna i plankton, jednak polują także na większe organizmy.
Organizmy te rozmnażają się płciowo i bezpłciowo. Formą rozmnażającą się bezpłciowo jest mały bentosowy polip ulegający strobilizacji. Dominuje stadium meduzy, która rozmnaża się płciowo. Zapłodnienie jest zewnętrzne, w wyniku którego powstaje larwa (planula)
Gatunek ten występuje dość powszechnie i nie jest wpisany do Czerwonej Księgi Gatunków Zagrożonych [3]
Atolla wyvillei, Atolla gigantea (Atolla jellyfish) – gatunek z rodziny Atollidae składającej się z jednego rodzaju Atolla. Cechą charakterystyczną dla osobników tego rodzaju jest m.in. większa liczba narządów zmysłów niż u innych krążkopławów. Pomiędzy kolejnymi ropaliami znajdują się macki. Ich parasol w części krańcowej jest pofałdowany.
礁环冠水母（學名：Atolla wyvillei）是钵水母纲冠水母目领状水母科环冠水母属之下的一個深海水母物種[1][2]。本物種分佈於全世界各地的海洋裡[3]；但《中国动物志》認為本物種只出現於在印度洋-西太平洋海域的菲律宾海、安达曼海、及日本的北海道至本州中部一带深水海域[2]。本物種的種小名源於是為了紀念挑戰者探險隊（英语：Challenger expedition）的首席科學家查尔斯·威维尔·汤姆森（Charles Wyville Thomson）爵士。
如同其他水中動物一樣，本物種是深紅色的。 本种伞部特别扁平，呈圆盘状，伞径70—120mm，伞高35—50mm[2]。 冠沟位于伞顶1/5处，在冠沟上面伞部中央厚而呈凸透镜状，在冠沟下面伞部有20—22条浅的放射辐沟（英语：radial furrow），將伞部分為20—22个缘叶（英语：pedalia）；另外還有一條比其餘更大的肥厚觸手[4]。這一條特長的肥厚觸手估計是用來捕食的[5]。
本物種能夠發光[6]：當本物種受到襲擊，就會發出一系列的閃光，從而將攻擊者暴露於其捕食者的視線範圍內[7]。
海洋生物學家Edith Widder為研究這種水母的發光機制，她基於本物種的發光模式而設計了一種名為「E-jelly」，以模仿礁环冠水母受到來自捕食者的威脅時所發出的閃光。這種電子水母成功吸引了深海中神秘而且罕見的動物進入攝錄機的紀錄範圍，使這些生物得以被紀錄。這次活動得到探索頻道及日本NHK電視台資助，讓她成功以鏡頭捕獲一隻巨烏賊的踪影[8]。
礁环冠水母（學名：Atolla wyvillei）是钵水母纲冠水母目领状水母科环冠水母属之下的一個深海水母物種。本物種分佈於全世界各地的海洋裡；但《中国动物志》認為本物種只出現於在印度洋-西太平洋海域的菲律宾海、安达曼海、及日本的北海道至本州中部一带深水海域。本物種的種小名源於是為了紀念挑戰者探險隊（英语：Challenger expedition）的首席科學家查尔斯·威维尔·汤姆森（Charles Wyville Thomson）爵士。
