Dallia pectoralis és una espècie de peix de la família Umbridae, nom que rep a un peix natiu de Sibèria i Alaska, capaç de mantenir-se amb vida congelat en un bloc de neu diverses setmanes. És un peix de grans aletes i grandària mitjana, mesurant 14 cm (7 polzades aprox) de longitud. El cos presenta un disseny de taques intricades sobre el seu llom i la vora de les seves aletes també, tots aquests de color marró atzabeja.
A aquest peix se li coneix per la seva capacitat de sobreviure dins del gel. En el seu estat natural, se submergeix de 7 a 8 metres quan la superfície de l'aigua es congela. Unes cobertes protectors en les seves agallas mantenen les artèries en funció, perquè ell segueixi respirant, de manera que, el peix es manté en activitat, encara si el seu cos està cobert de cristalls de gel. Malgrat aquesta supervivència, aquest peix no viu si la temperatura en el qual està sotmès tendeix a variar. La temperatura mitjana és de 0° Celsius (273 °F) i solament el peix sobreviu si la temperatura és constant.
Dallia pectoralis ist ein Süßwasserfisch aus der Ordnung der Hechtartigen (Esociformes). Er lebt in Alaska, den Inseln des Beringmeeres und am Ende der Tschuktschen-Halbinsel im nordöstlichen Sibirien.
Die Fische haben eine kurze, flache Schnauze und, wie die Hechte, weit nach hinten verlagerte Rücken- und Afterflossen. Die Kiemenreusefortsätze sind kurz. Das Seitenlinienorgan hat winzige Poren. Entlang der Körpermitte haben sie 76 bis 100 Schuppen. Die Brustflossen sind gerundet, die Bauchflossen sehr klein und stehen weit hinten, kurz vor dem Anus. Die Schwanzflosse ist breit und abgerundet.
Die Fische werden 33 Zentimeter lang. Sie sind oberseits dunkelgrün oder braun, die Unterseite ist hell mit dunkeln Flecken. Auf den Flanken haben sie vier bis sechs unregelmäßige dunkle Bänder oder Flecken. Rücken-, After und Schwanzflosse haben einen dunkelbraunen Rand, der bei laichbereiten Tieren rot oder rosafarben wird.
Flossenformel: Dorsale 10–14, Anale 12–16, Ventrale 3, Pectorale 33
Die Fische leben normalerweise in stark bewachsenen Sümpfen und Teichen, gelegentlich auch in mittleren und großen Flüssen und Seen mit reichlicher Vegetation. Sie wandern im Frühling von den Flussunterläufen stromaufwärts zu ihren Laichgründen und im Herbst zurück in tiefere Gewässer. Dallia pectoralis ist sehr kältetolerant und überlebt auch das teilweise Einfrieren. Die Fische können ihre Speiseröhre als zusätzliches Atemorgan nutzen.
Traditionell wird die Gattung Dallia in die Familie der Hundsfische (Umbridae) gestellt.[1] Phylogenetische Untersuchungen in letzter Zeit legen aber nahe, dass Dallia näher mit den Hechten (Esox) als mit Umbra verwandt ist; Dallia ist demnach die Schwesterart eines Taxons aus Esox und Novumbra hubbsi, einer weiteren Art, die traditionell in die Familie Umbridae gestellt wird. Alle drei Gattungen zusammen sind die Schwestergruppe von Umbra.[2][3] Wiley und Johnson ordneten Dallia deshalb in die Familie Esocidae ein.[4]
Neben Dallia pectoralis (dem „Alaskan blackfish“) wurden zwei weitere Arten der Gattung Dallia beschrieben, die aber wenig erforscht und vielleicht nur Synonyme zu Dallia pectoralis sind. Beide Arten leben im nordöstlichen Sibirien.[5]
Dallia pectoralis ist ein Süßwasserfisch aus der Ordnung der Hechtartigen (Esociformes). Er lebt in Alaska, den Inseln des Beringmeeres und am Ende der Tschuktschen-Halbinsel im nordöstlichen Sibirien.
The Alaska blackfish (Dallia pectoralis) is a species of freshwater fish in the esocid family (Esocidae) of order Esociformes. It inhabits Arctic regions of Alaska as well as Siberia and the Bering Sea islands.
Alaska blackfish are small, with an average length of 108 mm (4.3 in), but have been known to reach 330 mm (13 in).[3]
They have an easily distinguishable morphology (a branch of biology dealing with the study of the form and structure of organisms and their specific structural features), with relatively large, posterior dorsal fin and anal fins, large, lobed pectoral fins located just posterior to the operculum, a diphycercal caudal fin, and small, pointy pelvic fins.[4]
The head is broad and flat, with the trunk being long and slender. The color is dark green to brown on the dorsal side, pale below, with light-colored blotches appearing laterally.[4]
Males can be distinguished from females by the presence of a reddish fringe along the dorsal, caudal, and anal fins; also, the tips of the ventral fins extend beyond the anal fin in males, whereas in females they do not.[4][3]
The Alaska blackfish is famous for its ability to breathe atmospheric oxygen through a modified esophagus.[5] Specifically, the esophagus of a blackfish can be subdivided into a non-respiratory and a respiratory section. The respiratory section can be identified by its extensive mucosal folding and vascularization, as well as widespread capillaries throughout the epithelium.[5] This respiratory structure implies selection pressures for the development of a purely respiratory organ and a purely hydrostatic organ.[5] Another factor is the retention of the hydrostatic swim bladder, which seems unnecessary unless it is important in maintaining neutral buoyancy in the cold winter months under ice cover.[5]
Alaska blackfish can be found in the Bering Sea islands, Siberia, and Alaska.[3] In Alaska, they inhabit the Colville Delta south to the central Alaska Peninsula near Chignik as well as the upstream Yukon-Tanana drainage to near Fairbanks.[3]
Blackfish are found in highly vegetated swamps and ponds, occasionally residing in rivers and densely-vegetated lakes, where in summer, water is frequently stagnant.[4][5] Spawning migrations are limited to inshore and upstream movements in the spring, and reverse migrations to deeper water in the fall.[3]
In the winter-time, blackfish tend to reside in the benthic regions of lakes, although when oxygen availability reaches a certain minimum, blackfish move to the surface, grouping around breathing holes.[6] These breathing areas can be preexisting holes, such as those created by muskrats, beavers, and fishers, or simply thin layers of ice. Blackfish have been observed schooling below the ice, and when swimming upwards to breathe, eat away at the ice and creating an audible snapping or sucking sound.[6] The Alaska blackfish is known for its tolerance of cold water, and has been reported to survive exposure to −20 °C (−4 °F) for 40 minutes.[3] Despite its hardiness, Alaska blackfish have been observed to suffer edema and mass mortality events during the winter.[7]
The principal source of food for blackfish is aquatic insects and invertebrates, although in Bristol Bay, larger blackfish have been observed to be cannibalistic, as well as predators of young pike.[4] Blackfish are generalist feeders, and have been analyzed to have contained algae, snails, dipteran larvae, ostracods, copepods, and caddisfly larvae in their stomachs.[8]
Spawning occurs from May to August, with fish having the ability to spawn several times; thus, females do not usually expel their entire egg contents in a single event.[4]
A female, depending on her size, can release a total of 40-300 eggs at intervals during the spawning period, with the eggs then attaching to vegetation and hatching in a short period of time (nine days at 12 °C (54 °F)).[4] When the young hatch, they are approximately 6 mm in length, and survive off the yolk sac for an average period of 10 days.[4]
Rate of growth varies throughout Alaska, with blackfish from Interior Alaska and the Anchorage area being about 108 mm (4.3 in) at age 2, 138 mm (5.4 in) at age 3, and 178 mm (7.0 in) at age 4. On the other hand, Bristol Bay blackfish are much slower growing and longer lived. Four-year-old fish are approximately 64 mm (2.5 in) in length, but can live up to 8 years.[4] Female blackfish have been shown to reach sexual maturity at 80 mm (3.1 in).[4]
The Alaska blackfish is an important subsistence fish for Native communities residing in the Interior and Western Alaska, specifically those residing in Interior Alaska.[6] Although generally small (average size is 108 mm (4.3 in)),[3] their significance comes in their high nutritional value and large abundance in the winter, a generally lean time of year.[6]
When oxygen levels in the benthic regions of lakes becomes low, blackfish move to the surface to obtain atmospheric oxygen, thus making ice fishing an easy method of capture; blackfish are commonly stored, frozen, and then fed to dogs, with certain Alaskan stories recollecting moments when blackfish would seemingly revive themselves upon thawing.[6] Metabolic and survival studies have been conducted without successful replication of this observation.
The Alaska blackfish is not International Union for Conservation of Nature-listed as an endangered or threatened species.[3] While blackfish are native to Western Alaska as well as the Interior, they were introduced to the Cook Inlet Basin of Alaska in the 1950s, and have since become widespread.[9] A study performed by Eidam et.al. (2016) in three study sites in the Cook Inlet Basin concluded that an insignificant portion of their diet was fish, meaning blackfish are unlikely to impact native and stocked fish in those populations. While that information is helpful for determining whether blackfish are truly invasive, it is not all-encompassing for other blackfish populations in the area. Further studies are warranted that estimate the abundance of introduced blackfish in lakes and streams in the Cook Inlet Basin, as well as investigate potential dietary overlap with other fish.
Molecular study of Alaska blackfish across its range has identified several geographic areas where Alaska blackfish persisted during glacial episodes.[10][11] Genetic structuring within the species is relatively high for a fish species from northern latitudes, most likely reflecting biological characteristics such as poor dispersal ability and winter survival.[10][11][12]
The Alaska blackfish (Dallia pectoralis) is a species of freshwater fish in the esocid family (Esocidae) of order Esociformes. It inhabits Arctic regions of Alaska as well as Siberia and the Bering Sea islands.
Pez negro de Alaska. Nombre que recibe a un pez nativo de Siberia y Alaska, capaz de mantenerse con vida congelado en un bloque de nieve varias semanas. Es un pez parduzco de grandes aletas y tamaño mediano, midiendo 14 cm (7 pulgadas aprox) de longitud. El cuerpo presenta un diseño de manchas intrincadas sobre su lomo y el borde de sus aletas también, todos éstos de color pardo azabache.
A este pez se le conoce por su capacidad de sobrevivir dentro del hielo. En su estado natural, se sumerge de 7 a 8 metros cuando la superficie del agua se congela. Unas cubiertas protectoras en sus agallas mantienen las arterias en función, para que él siga respirando, de modo que, el pez se mantiene en actividad, aún si su cuerpo está cubierto de cristales de hielo. A pesar de dicha supervivencia, este pez no vive si la temperatura en el que está sometido tiende a variar. La temperatura promedio es de 0º Celsius (273 ºF) y solamente el pez sobrevive si la temperatura es constante.
Dallia pectoralis Bean, 1880 è un pesce osseo d'acqua dolce della famiglia Umbridae.
L'areale della specie comprende l'Alaska, le isole del mar di Bering e una piccola parte della Siberia nordorientale[1].
Vive principalmente in stagni e piccoli laghi della tundra subartica, in ambienti ricchi di vegetazione acquatica. Più di rado si può incontrare in fiumi e laghi di grandi dimensioni[1].
Dallia pectoralis ha un corpo slanciato e affusolato, con testa piuttosto piccola e appiattita. Le pinne dorsale e anale sono simmetriche, con bordo arrotondato, e inserite molto indietro sul corpo, appena anteriormente al tozzo peduncolo caudale. La pinna caudale è grande e arrotondata. Le pinne ventrali sono piccolissime, ridotte a 3 raggi e sono inserite appena davanti all'ano; le pinne pettorali sono invece ampie e arrotondate. Non ci sono raggi spinosi sulle pinne. Le scaglie sono molto piccole[1].
La livrea è brunastra o verdastra scura su dorso e fianchi e chiara con macchie scure sul ventre. Tutto il corpo e le pinne sono cosparsi di punti scuri, sono inoltre presenti da 4 a 6 fasce verticali scure indistinte. Le pinne pari hanno un bordo chiaro che diventano da rosa a rossi negli individui in livrea nuziale[1].
Le dimensioni sono contenute, attorno ai 10 cm in media; la taglia massima conosciuta è di 33 cm per 366 grammi di peso[1].
Questo pesce è noto per la sua straordinaria resistenza alle basse temperature: può sopportare temperature di -20 °C per 40 minuti e il congelamento di parti del corpo per più giorni. Può respirare ossigeno atmosferico dall'esofago. Può vivere fino a 8 anni[1].
Oviparo. Può affrontare alcune brevi migrazioni riproduttive[1].
La pesca è limitata alla pesca di sussistenza delle popolazioni indigene[1].
Dallia pectoralis Bean, 1880 è un pesce osseo d'acqua dolce della famiglia Umbridae.
De grote waaiervis (Dallia pectoralis) is een vis uit de familie Umbridae (Umbridae), orde Snoekachtigen (Esociformes).
Deze vis kan maximaal 33 centimeter worden met een gewicht van 375 gram. De vis is lang en cilindervormig, heeft een stompe kop met een grote bek met vooruitstekende onderkaak en afgeronde vinnen. Het lichaam heeft een donkere olijfbruine kleur en een witte buik. De vinnen hebben roodbruine vlekken. Het mannetje krijgt in de paartijd rode vinranden.
Hun voornaamste voedsel van deze traag zwemmende vissen bestaat uit insectenlarven van de dans- en de steekmuggen, maar ook slakken en kleine vissen staan op het menu. Deze worden gevangen vanuit een hinderlaag in een zeer korte sprint.
Ze worden aangetroffen in moerassen, meertjes en beekjes met vegetatie waarin de vis zich kan verschuilen. Ze worden gevonden tussen Alaska en de eilanden van de Beringzee.
Ze staan bekend om hun overlevingskracht. Ze overleven koude winters door naar een diepte van zeven tot acht meter te verhuizen wanneer de oppervlakte bevriest. Grote kieuwen, bedekt met kieuwplaten helpen de vis te overleven in water van 0 °C en er zijn zelfs verhalen over tot leven komende exemplaren na bevroren te zijn. De lichaamsvloeistoffen bevatten glycoproteïnen die als antivriesmiddel dienen, en zolang deze niet bevriezen overleven zij de koude.[1] Ze schijnen korte tijd temperaturen van -20 °C te overleven in gecontroleerde omstandigheden indien ze niet in contact komen met ijskristallen, maar er is geen wetenschappelijk bewijs dat de vis langer dan een uur kan overleven in deze omstandigheden. Ze kunnen ook overleven in zuurstofarme, stilstaande wateren door lucht te happen.
De grote waaiervis (Dallia pectoralis) is een vis uit de familie Umbridae (Umbridae), orde Snoekachtigen (Esociformes).
Multimedia w Wikimedia Commons 
Hasło w Wikisłowniku Dalia[2], czarna ryba[2] (Dallia pectoralis) – gatunek słodkowodnej ryby z rodziny muławkowatych (Umbridae).
Żyje masowo w niewielkich rzekach, jeziorach i bagnach tundry na Alasce i Syberii. Przez prawie 7 miesięcy w roku przebywa w stanie hibernacji zamarznięta w lodzie lub zagrzebana w mule.
Jest to ciemno ubarwiona ryba o długości ok. 20 cm. Na płetwach i po bokach ciała wiele czarnych plam. Ikrę składa w czerwcu i lipcu.
Ma niewielkie, lokalne znaczenie gospodarcze.
Dalia, czarna ryba (Dallia pectoralis) – gatunek słodkowodnej ryby z rodziny muławkowatych (Umbridae).
Dallia pectoralis, conhecido em inglês como Alaska blackfish, é um peixe da família Umbridae. De formato alongado e cilíndrico e coloração marrom-oliva, ele chega a cerca de 18 centímetros de comprimento. Nos laterais do corpo ele possui de quatro a seis faixas escuras verticais, e a sua barriga é branca. As barbatanas possuem manchas marrom-avermelhadas.
Antigamente acreditava-se que este peixe fosse herbívoro, mas hoje sabe-se que sua dieta principal consiste de larvas de insetos como midges e mosquitos. Eles são encontrados em pântanos, lagos, lagoas e riachos que possuem vegetação de cobertura, localizados na tundra e em florestas. A área em que o Dallia pectorais vive vai do Alasca às ilhas do Mar de Bering. Os nativos do Alasca costumavam comer esse peixe e usá-lo para alimentar os seus cães, pescando-o no outono e congelando-o para utilizá-lo no inverno.
A resistência desse peixe é notável. Ele sobrevive a invernos rigorosos deslocando-se para uma profundidade de 7 a 8 metros quando a superfície congela inteiramente. As guelras protegidas por grandes opérculos o ajudam a sobreviver ao inverno quando a temperatura da água cai para 0°C, e há lendas de peixes que “voltaram à vida” após estarem completamente congelados. Embora o Alaskan blackfish possa ser super-resfriado por períodos curtos a temperaturas inferiores a -20°C em ambientes controlados, sem contato com cristais de gelo, nenhum espécime jamais sobreviveu por sequer uma hora a tais condições de congelamento em ambiente natural, já que o congelamento de qualquer parte do corpo resultaria em necrose.
Dallia pectoralis, conhecido em inglês como Alaska blackfish, é um peixe da família Umbridae. De formato alongado e cilíndrico e coloração marrom-oliva, ele chega a cerca de 18 centímetros de comprimento. Nos laterais do corpo ele possui de quatro a seis faixas escuras verticais, e a sua barriga é branca. As barbatanas possuem manchas marrom-avermelhadas.
Antigamente acreditava-se que este peixe fosse herbívoro, mas hoje sabe-se que sua dieta principal consiste de larvas de insetos como midges e mosquitos. Eles são encontrados em pântanos, lagos, lagoas e riachos que possuem vegetação de cobertura, localizados na tundra e em florestas. A área em que o Dallia pectorais vive vai do Alasca às ilhas do Mar de Bering. Os nativos do Alasca costumavam comer esse peixe e usá-lo para alimentar os seus cães, pescando-o no outono e congelando-o para utilizá-lo no inverno.
A resistência desse peixe é notável. Ele sobrevive a invernos rigorosos deslocando-se para uma profundidade de 7 a 8 metros quando a superfície congela inteiramente. As guelras protegidas por grandes opérculos o ajudam a sobreviver ao inverno quando a temperatura da água cai para 0°C, e há lendas de peixes que “voltaram à vida” após estarem completamente congelados. Embora o Alaskan blackfish possa ser super-resfriado por períodos curtos a temperaturas inferiores a -20°C em ambientes controlados, sem contato com cristais de gelo, nenhum espécime jamais sobreviveu por sequer uma hora a tais condições de congelamento em ambiente natural, já que o congelamento de qualquer parte do corpo resultaria em necrose.
Alaska karabalığı (Dallia pectoralis), Umbridae familyasından, Alaska'da ve Bering Denizi adalarında yaygın olan uzun ve silindirik bir tatlı su balık türü. 180 mm boyundadır.
Alaska Eskimoları ve Alaska Atabaskları başta olmak üzere Alaska yerlileri tarafından sonbaharda avlanarak dondurulur ve kışın kendileri ya da köpekleri için tüketmek üzere saklanır. Koyukonlar (oonyeeyh) açlığın görüldüğü kış sonu ilkbahar başında hayati öneme sahip olan Alaska karabalıklarını buz altında oltayla avlarlar[1]. Yupikler (canʼgiiq) ve Nunivak Çupikleri (canʼgir) tarafından avlanan balıklardandır[2].
Alaska karabalığı (Dallia pectoralis), Umbridae familyasından, Alaska'da ve Bering Denizi adalarında yaygın olan uzun ve silindirik bir tatlı su balık türü. 180 mm boyundadır.
Даллия, или обыкновенная даллия, или чёрная рыба[1] (лат. Dallia pectoralis) — вид лучепёрых рыб семейства щуковых. Широко распространены в водоёмах Чукотки и Аляски.
Спинной и анальный плавники сдвинуты к хвостовой части тела. В спинном плавнике 10—16 мягких лучей, а в анальном плавнике 11—16 мягких лучей. Грудные плавники очень большие с 30—38 лучами, в брюшных плавниках три луча. Хвостовой плавник закруглённый. Боковая линия зачаточная, чешуйки мелкие, погружены в кожу.
Достигают длины 33 см, обычно около 11 см. Максимальная масса тела 366 г[2].
Тело чёрно-коричневое. Спинной, хвостовой и анальный плавники окаймлены тонкой оранжевой полосой, которая становится красной в период нереста. Самцы ярче, крупнее самок
Водоёмы Чукотки; а также на Аляске.
Обитают в небольших речках, озёрах и болотах; в период размножения перемещаются по ручьям. На зиму закапывается в ил и часто вмерзает в лёд, долгое время оставаясь живой, но всё же в значительном количестве гибнет.
На Чукотке впервые созревают в возрасте 3—4 года при длине тела 6—7 см, на Аляске самки достигают половой зрелости при длине 80 мм. Нерестятся с мая до августа. В течение нерестового периода самка вымётывает несколько порций икры с определёнными интервалами. Плодовитость варьируется от 40 до 300 икринок в зависимости от размера самок. Икра клейкая, прикрепляется к водной растительности. Продолжительность инкубационного периода при 12°С составляет 5 дней. Длина вылупившихся предличинок 6 мм. Желточный мешок рассасывается примерно через 10 дней[3].
Даллии питаются преимущественно водными беспозвоночными. Основу рациона составляют ракушковые, ветвистоусые раки и личинки двукрылых. Также в желудках встречаются брюхоногие, веслоногие ракообразные, личинки ручейников, черви и водоросли. В реках Бристольского залива существенную роль в питании крупных особей даллий играют молодь собственного вида и щуки[3][4].
Даллия, или обыкновенная даллия, или чёрная рыба (лат. Dallia pectoralis) — вид лучепёрых рыб семейства щуковых. Широко распространены в водоёмах Чукотки и Аляски.
阿拉斯加黑魚為輻鰭魚綱狗魚目泥狗魚科的其中一種，分布於美國阿拉斯加、白令島、加拿大育空地方及俄羅斯西伯利亞東北部的淡水流域。本魚體短，鼻部扁平，體為暗綠色或褐色，背鰭軟條10-14枚;臀鰭軟條12-16枚，體長可達33公分。棲息在植物生長茂盛的池塘、沼澤或小溪，繁殖期在春季，秋季時會遷徙到較深水域，屬肉食性，可作為食用魚或觀賞魚。
