Limacina helicina helicina is a traditionally recognized subspecies of the shelled pteropod mollusk Limacina helicina, a key organism in polar pelagic ecosystems, where it can can account for 50% of total zooplankton abundance (number of individuals per unit volume). Pteropods are strictly pelagic mollusks that are highly adapted to life in the open ocean. They are commonly referred to as ‘‘sea butterflies’’ due to their wing-like parapodia, which are evolutionary modifications of the gastropod foot. Pteropods produce large mucus webs to filter-feed on phytoplankton as well as small zooplankton (including their own juveniles). Species of the Order Thecosomata, including L. helicina (the only thecosome pteropod in Arctic waters), produce a fragile external calcium carbonate (aragonite) shell. Shelled pteropods play a significant geochemical role in the oceans, as they contribute to the export of calcium carbonate and can represent a major component of the carbon transport to the deep ocean. The likely effects of ocean acidification (resulting from the absorption of increasing quantities of CO2 from the atmosphere) have been studied in a variety of shell-building marine organisms, including L. helicina, which may be especially vulnerable as a result of its aragonite shell and its distribution in polar oceans, which acidify especially quickly due to their particular chemical and physical characteristics. (Comeau et al. 2010 and references therein; Hunt et al. 2010)
Although L. helicina was formerly believed to have a bipolar distribution, further investigation has shown that the Arctic and Antarctic forms are genetically distinct species. Traditionally, northern and southern hemisphere forms were recognized as subspecies and referred to as L. h. helicina and L. h. antarctica, respectively. Three morphotypes, or "forma", of the subspecies L. h. helicina have often been recognized (acuta, helicina, and pacifica) along with two morphotypes of L. h. antarctica (antarctica and rangi). However, genetic studies have revealed that L. h. helicina and L. h. antarctica differ by around 34% in mitochondrial COI sequence, far more divergence than would be seen intraspecifically. Sequence data are not yet available to help clarify the taxonomic status of the various morphotypes, which may or may not actually be genetically distinct. (Hunt et al. 2010)
The shelled pteropod mollusk Limacina helicina is a key organism in polar pelagic ecosystems, where it can can account for 50% of total zooplankton abundance (number of individuals per unit volume). Pteropods are strictly pelagic mollusks that are highly adapted to life in the open ocean. They are commonly referred to as ‘‘sea butterflies’’ due to their wing-like parapodia, which are evolutionary modifications of the gastropod foot. Pteropods produce large mucus webs to filter-feed on phytoplankton as well as small zooplankton (including their own juveniles). Species of the Order Thecosomata, including L. helicina (the only thecosome pteropod in Arctic waters), produce a fragile external calcium carbonate (aragonite) shell. Shelled pteropods play a significant geochemical role in the oceans, as they contribute to the export of calcium carbonate and can represent a major component of the carbon transport to the deep ocean. The likely effects of ocean acidification (resulting from the absorption of increasing quantities of CO2 from the atmosphere) have been studied in a variety of shell-building marine organisms, including L. helicina, which may be especially vulnerable as a result of its aragonite shell and its distribution in polar oceans, which acidify especially quickly due to their particular chemical and physical characteristics. (Comeau et al. 2010 and references therein; Hunt et al. 2010)
Although L. helicina was formerly believed to have a bipolar distribution, further investigation has shown that the Arctic and Antarctic forms are genetically distinct species. Traditionally, northern and southern hemisphere forms were recognized as subspecies and referred to as L. h. helicina and L. h. antarctica, respectively. Three morphotypes, or "forma", of the subspecies L. h. helicina have often been recognized (acuta, helicina, and pacifica) along with two morphotypes of L. h. antarctica (antarctica and rangi). However, genetic studies have revealed that L. h. helicina and L. h. antarctica differ by around 34% in mitochondrial COI sequence, far more divergence than would be seen intraspecifically. Sequence data are not yet available to help clarify the taxonomic status of the various morphotypes, which may or may not actually be genetically distinct. (Hunt et al. 2010)
Limacina helicina is a species of small swimming planktonic sea snail in the family Limacinidae, which belong to the group commonly known as sea butterflies (Thecosomata).[7][8]
Limacina helicina is a keystone species of mesozooplankton in Arctic pelagic ecosystems.[9][10][11]
The first written record of this species was by Friderich Martens from Spitsbergen in 1675.[12][13] Limacina helicina was also observed during a 1773 expedition to the Arctic led by Constantine John Phipps on the ships HMS Racehorse and on HMS Carcass and the species was described one year later, in 1774.[1]
Limacina helicina is the type species of the genus Limacina.[14]
In contrast to the traditional view, it was shown in 2010 that the distribution of this species is not bipolar; Arctic and Antarctic individuals belong to two genetically distinct species: Limacina helicina in the Arctic, and Limacina antarctica in the Antarctic.[11][15]
Limacina helicina has been recognised as a species complex comprising two sub-species and at least five forms.[15] In addition, the taxonomic category “forma” has been applied to designate at least three morphotypes of Limacina helicina helicina (acuta, helicina and pacifica) and two morphotypes of Limacina helicina antarctica (antarctica and rangi).[15] It is also known as Limacina helicina rangii (d'Orbigny, 1835).[16] These forms typically have different geographical ranges, but it remains unclear as to whether forms represent morphological responses to different environmental conditions or are indeed taxonomically distinct, and if the latter, their level of taxonomic separation.[15]
However, at the species level the geographical distribution is considered to be bipolar, as it occurs in both the Arctic and Antarctic oceans.[15] Remigio and Hebert (2003)[19] provided initial evidence for the genetic separation of Limacina helicina helicina and Limacina helicina antarctica.[15] Hunt et al. (2010)[15] have quantified genetic distance within these taxa. Hunt 2010 found a 33.56% difference in cytochrome c oxidase subunit I (COI) gene sequences between the "Limacina helicina" which were collected from the Arctic and the Antarctic oceans.[15] This degree of separation is sufficient for ordinal level taxonomic separation in other organisms, and provides strong evidence for the Arctic and Antarctic populations of Limacina helicina differing at least at the species level.[15] Subspecies Limacina helicina antarctica Woodward, 1854 can be considered as a separate species Limacina antarctica Woodward, 1854.[16] A conservative divergence time estimate of 31 Ma (95% HPD interval 12–53 Ma) for Arctic and Antarctic taxa, indicates that they have undergone rapid independent evolution since the establishment of cold water provinces in the early Oligocene.[15] Also there is different structure of the shell between Limacina helicina and Limacina antarctica.[9]
The type locality of Limacina helicina is "Arctic seas".[1] Limacina helicina is the only thecosome pteropod in Arctic waters.[11]
The distribution of Limacina helicina is arctic and subarctic (subpolar–polar)[20] especially in the Arctic Ocean and countries include:
Limacina helicina has wing-like parapodia which evolved from the original gastropod foot (as is the case in all other pteropods).[11]
In this species, the color of the soft parts is dark purple or violet, with paler pellucid (translucent) parapodia.[24]
The shell is sinistral, subglobose, subdiscoidal,[25] hyaline and very thin. The spire is depressed[25][26] but it can be considered rather high in comparison of other Limacina species.[21] The shell has 5-6 transversally striated whorls.[21][26] The suture is distinct.[21] The last whorl is large and with very obscure keel next to its umbilicus.[21][25] The shell has a wide umbilicus.[21] The aperture is higher than it is wide.[21]
The width of the shell is 5–10 mm[10] or up to 13 mm.[13] The height of the shell is up to 6 mm (when maximum width was 8 mm).[21]
Adult specimens in the genus Limacina have usually lost the operculum.[21]
The radula consist of 10 rows.[24] Each row consist of one central tooth and two lateral teeth.[24] The Digestive system also includes an esophagus, gizzard sac and gut.[13]
Pteropods are strict pelagic mollusks that are highly adapted to life in the open ocean.[11] They are actively swimming in the water. Limacina helicina is a holoplanktonic species. Habitat of Limacina helicina is upper epipelagic and glacial.[16] It lives in temperatures from -0.4 °C to +4.0 °C or rarely up to 7 °C.[27]
Vertical distribution is affected by the size and also by other factors.[28] Limacina helicina of the size from 0.2 to 0.4 mm lives mainly in depths from 0 m to 50 m.[28] Larger pteropods lives from 0 m to 150 m.[28] For example, Gilmer & Harbison (1991)[13] have found larger specimen of Limacina helicina to occur mainly in depths 5–25 m with abundance up to 2.5 adults in m3.[13] They do not occur much in upper 4 m probably because of turbulence.[13]
Already Constantine John Phipps mentioned its "innumerable quantities" in arctic seas in 1774.[1] Limacina helicina is a major component of the polar zooplankton.[15] It can comprise>50% of total zooplankton abundance (number of individuals per unit volume).[15]
Species of the clade Thecosomata produce a fragile external calcium carbonate shell, which could serve as a ballast enabling large vertical migrations and as a protection against predators.[11] The aragonitic composition of the shell makes it very sensitive to dissolution.[11] Aragonite is a metastable form of calcium carbonate and it is more soluble in seawater than calcite.[10] Because of its highly soluble[11] aragonite shell and polar distribution, Limacina helicina may be one of the first organisms affected by ocean acidification, and it is therefore a key indicator species of this process.[15] As a key indicator of the acidification process, and a major component of polar ecosystems, Limacina helicina has become a focus for acidification research.[15] Based on laboratory experiments, they are able to precipitate calcium carbonate at low aragonite saturation state.[11] Limacina helicina seems to be relatively more resilient to elevated concentration of carbon dioxide (CO2) than other aragonitic organisms such as corals.[11] Laboratory experiments results support the current concern for the future of Arctic pteropods, as the production of their shell appears to be very sensitive to decreased pH.[10][11] A decline of pteropod populations would likely cause dramatic changes to various pelagic ecosystems.[10][11] However, in response to acute abiotic stress, Limacina helicina shows high transcriptomic plasticity,[29] suggesting this species may have a limited capacity to acclimate to the effects of ocean acidification and ocean warming. Shelled pteropods also play a geochemical role in carbon cycle in the oceans, as they contribute to the export of calcium carbonate and can represent a major component of the carbon transport to the deep ocean.[10][11][15]
Researchers found 24-53% individuals of Limacina helicina with shells damaged by dissolution off the U.S. West Coast in 2011.[30]
They produce large mucus webs to filter-feed on phytoplankton but also small zooplankton.[11] They eat the web with the captured prey and then re-reproduce a web net.[26] The web is large and spherical[31] and it is difficult to see during the day because of diffuse reflection.[13] Webs are easier to see at night.[13] Limacina helicina is easily disturbed (like all other Thecosomata); when disturbed, it retracts into its shell and destroys its web.[13] Gilmer & Harbison (1991)[13] have assumed, that Limacina helicina feeds while motionless (without actively swimming).[13] Its web enables them neutral buoyancy or allows them slow sinking only.[31]
Limacina helicina plays a significant ecological role as a phytoplankton grazer.[15] Limacina helicina is an obligate ciliary feeder.[28] Gilmer & Harbison (1991)[13] hypothesized that Limacina helicina are "web trappers", who are also chemically attracting their motile prey.[13]
Major parts of the food of Limacina helicina include tintinnid (Tintinnida), small crustaceans - copepods (Copepoda) and juvenile specimen of its own species (cannibalism).[13] Danish zoologist Johan Erik Vesti Boas reported diatoms (Bacillariophyceae), dinoflagellates (Dinoflagellata) and tintinnids in the digestive system of Limacina helicina in 1888 already.[32] Diatoms and dinoflagellates appear to pass the digestive system of adults largely intact.[8][13] Fecal pellets of Limacina helicina contains small cells, dinoflagellates and diatoms as main largely intact food items and also few small fragments of tintinnids, Limacina and copepods.[13] All experiments performed on Limacina helicina in the laboratory were done on starved specimens, because they do not feed in unnatural conditions.[13] Ocean acidification and ocean warming may cause Limacina helicina to increase its metabolic rate and use more storage compounds, especially during the Arctic winter when food is limited. This may result in a decline in reproductive success and survival.[33]
Gilmer & Harbison (1991)[13] also suggested that smaller specimens may be herbivores feeding preferentially on phytoplankton and protozoans and that larger specimens became omnivores.[13]
Limacina helicina is a protandric hermaphrodite.[8][28] Males are smaller, at sizes of 4–5 mm[8] and then they change to females, which are larger than 5 mm.[8] Sperm is transferred by spermatophores during copulation.[34] They lay eggs in ribbon-like clusters[8] mainly in summer, but also a little in winter.[28]
The size of the veliger larvae is about 0.15 mm.[26] When animals reached 0.7 mm in size, gonads have been detected in them.[28] Fully mature individuals are 0.8 mm in size.[28]
The life cycle of Limacina helicina lasts about 1 year[8] or 1.5–2 years.[28]
Limacina helicina plays an important role in the marine food web as a major dietary component for predators such as large zooplankton, herring Clupea sp.,[22] chum salmon Oncorhynchus keta,[22] pink salmon Oncorhynchus gorbuscha,[22] rorquals,[22][27] Phoca hispida[27] and other seals[27] and birds.[11]
The pteropod Clione limacina feeds almost entirely on the genus Limacina: on Limacina helicina and on Limacina retroversa.[34][35][36] Also the pteropod Paedoclione doliiformis feeds on those two species only, but solely on juveniles with shells smaller than 1 mm.[34]
Limacina helicina possesses a pair of flexible, wing-like appendages called parapodia which it beats in a complex 3D stroke pattern which resembles the wing kinematics of flying insects. By doing so, the animal effectively flies through the water. The sea butterfly uses a high angle of attack of approximately 45-50 degrees to generate lift, and it beats its wings 4 to 10 times per second. It propels itself using a version of the clap and fling mechanism described by Torkel Weis-Fogh in small insects such as thrips.[37][38] Another aspect of locomotion by Limacina helicina is the extreme, forward-back pitching (called hyper-pitching) which it experiences during each half-stroke of its wings. The animal rocks forward and backward by up to 60 degrees during each half-stroke. No other species is known to experience such extreme hyper-pitching during normal locomotion.[38][39]
This article incorporates CC-BY-2.5 text from the reference [11][15] and public domain text from the reference [25]
{{cite journal}}: Check |url= value (help) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) Limacina helicina is a species of small swimming planktonic sea snail in the family Limacinidae, which belong to the group commonly known as sea butterflies (Thecosomata).
Limacina helicina is a keystone species of mesozooplankton in Arctic pelagic ecosystems.
The first written record of this species was by Friderich Martens from Spitsbergen in 1675. Limacina helicina was also observed during a 1773 expedition to the Arctic led by Constantine John Phipps on the ships HMS Racehorse and on HMS Carcass and the species was described one year later, in 1774.
Limacina helicina is the type species of the genus Limacina.
In contrast to the traditional view, it was shown in 2010 that the distribution of this species is not bipolar; Arctic and Antarctic individuals belong to two genetically distinct species: Limacina helicina in the Arctic, and Limacina antarctica in the Antarctic.
Limacina helicina est une espèce d'escargot de mer prédateur de la famille des Limacinidae, qui appartiennent au groupe communément appelé papillons de mer (Thecosomata).
C'est une espèce clef de mésozooplancton de l'écosystème de l'océan Atlantique pélagique. Elle a été mentionnée pour la première fois dans le récit de voyage de Friderich Martens Spitzbergischer oder Grönländischer Reise-Beschreibung, gethan im Jahre 1671, paru en 1675[1]. Elle a aussi été observée en 1773 lors de l'expédition en Arctique de Constantine John Phipps, qui l'a décrite l'année suivante[2].
En 2010, il a été démontré que les populations de l'Arctique et de l'Antarctique constituaient en fait deux espèces génétiquement distinctes : Limacina helicina dans l'Arctique et Limacina antarctica dans l'Antarctique.
Des chercheurs ont montré en 2009 que la coquille du papillon de mer se construit moins rapidement à cause de l'acidification des océans, menaçant l'espèce[3].
Photo d'un animal vivant
Dessin de 1878
L'animal est pourpre ou violet, avec les « ailes » translucides. Sa coquille mesure jusqu'à 14 mm de diamètre[4].
Selon World Register of Marine Species (15 févr. 2011)[5] :
Limacina helicina est une espèce d'escargot de mer prédateur de la famille des Limacinidae, qui appartiennent au groupe communément appelé papillons de mer (Thecosomata).
Limacina helicina is een slakkensoort uit de familie van de Limacinidae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1774 door Phipps.
Bronnen, noten en/of referenties
Limacina helicina é uma espécie de caramujo marinho conhecido vulgarmente como borboleta-do-mar, que pode ser encontrada nos oceanos Ártico e Antártico.
Limacina helicina é uma espécie de caramujo marinho conhecido vulgarmente como borboleta-do-mar, que pode ser encontrada nos oceanos Ártico e Antártico.
uol ciência e saúdeLimacina helicina là một loài ốc biển săn mồi bơi nhỏ trong họ Limacinidae, thuộc nhóm có tên gọi thông dụng là bướm biển (Thecosomata).[7][8]
Limacina helicina là một loài có đặc điểm của mesozooplankton trong hệ sinh thái biển khơi Bắc Cực.[9][10][11]
Các ghi chép đầu tiên của loài này do Friderich Martens ghi lại tại Spitsbergen vào năm 1675.[12][13] Limacina helicina cũng được quan sát thấy trong một chuyến thám hiểm năm 1773 đến Bắc Cực của John Constantine Phipps trên tàu HMS Racehorse và HMS Carcass và loài này đã được mô tả trong một năm sau, vào năm 1774.[1]
Limacina helicina là loài điển hình của chi Limacina.[14]
Ngược lại với quan điểm truyền thống, năm 2010 người ta chứng minh rằng sự phân bố của loài này là không lưỡng cực; các cá thể sinh sống ở Bắc Cực và Nam Cực thuộc hai loài khác biệt về mặt di truyền. Limacina helicina ở Bắc Cực, và Limacina antarctica ở Nam Cực.[11][15]
Bài viết về Lớp Chân bụng này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Limacina helicina là một loài ốc biển săn mồi bơi nhỏ trong họ Limacinidae, thuộc nhóm có tên gọi thông dụng là bướm biển (Thecosomata).
Limacina helicina là một loài có đặc điểm của mesozooplankton trong hệ sinh thái biển khơi Bắc Cực.
Các ghi chép đầu tiên của loài này do Friderich Martens ghi lại tại Spitsbergen vào năm 1675. Limacina helicina cũng được quan sát thấy trong một chuyến thám hiểm năm 1773 đến Bắc Cực của John Constantine Phipps trên tàu HMS Racehorse và HMS Carcass và loài này đã được mô tả trong một năm sau, vào năm 1774.
Limacina helicina là loài điển hình của chi Limacina.
Ngược lại với quan điểm truyền thống, năm 2010 người ta chứng minh rằng sự phân bố của loài này là không lưỡng cực; các cá thể sinh sống ở Bắc Cực và Nam Cực thuộc hai loài khác biệt về mặt di truyền. Limacina helicina ở Bắc Cực, và Limacina antarctica ở Nam Cực.
