Galaxias is 'n vis genus wat hoort tot die familie Galaxiidae. Die genus bestaan uit klein vissies, almal met silindriese lywe en sonder skubbe. Die dorsale vin is agter op die rug. Die meeste spesies is varswater visse maar party spesies kom voor in strandmere en party is diadrome vissoorte - hulle migreer tussen vars en seewater.
Die volgende spesie is die enigste een wat in Afrika voorkom:
Galaxias is 'n vis genus wat hoort tot die familie Galaxiidae. Die genus bestaan uit klein vissies, almal met silindriese lywe en sonder skubbe. Die dorsale vin is agter op die rug. Die meeste spesies is varswater visse maar party spesies kom voor in strandmere en party is diadrome vissoorte - hulle migreer tussen vars en seewater.
Galaxias és un gènere de peixos de riu de la família dels galàxids, distribuïts per aigües fluvials de clima temperat de l'hemisferi Sud: Oceania, Amèrica del Sud i Sud-àfrica.
Galaxias és un gènere de peixos de riu de la família dels galàxids, distribuïts per aigües fluvials de clima temperat de l'hemisferi Sud: Oceania, Amèrica del Sud i Sud-àfrica.
Galaxias is a genus of small freshwater fish in the family Galaxiidae, and are frequently referred to as the galaxiids. These highly adaptable fish are typically found at temperate latitudes across the Southern Hemisphere.
Galaxiids are scaleless and somewhat tubular in body form, ranging from very slender to quite bulky. They are somewhat torpedo-shaped, with the dorsal and anal fins positioned close to the tail. They are generally small, with typical adults ranging between 4–15 cm (1.6–5.9 in) in total length, with some stocky species attaining around 25 cm (10 in). The largest, Galaxias argenteus, has been recorded at 58 cm (22.8 in; 1.9 ft), although 30–40 cm (12–16 in) is a more typical adult length.
The 46 recognized species in this genus are:
Galaxiids are restricted to the Southern Hemisphere, and generally only occur in temperate latitudes. Only one species is known from subtropical habitats.[3]
Galaxiids are the dominant group of native freshwater fish in New Zealand, and, along with the Percichthyidae, one of two dominant groups of native freshwater fish in southeastern Australia. Only one of the species (G. zebratus) is found in Africa, and only three (G. globiceps, G. maculatus, and G. platei) are found in South America.
Galaxiids are coolwater species, with many wholly freshwater species specialising in high-altitude upland streams (including very small streams), rivers, and lakes. Some galaxiids include a marine stage in their lifecycles where larvae are washed out to sea to develop, and return to rivers as juveniles. This type of diadromous fish migration is known as amphidromy. These species are consequently also found in low-altitude habitats, but frequently migrate to high-altitude reaches of river systems in their adult stage.
Wholly freshwater galaxiids are gravely threatened by exotic salmonid species, particularly exotic trout species, which prey heavily upon them and compete with them for food and habitat. This is a major concern, as exotic trout species have been introduced to many different land masses (e.g. Australia, New Zealand, South Africa) with no thought as to impacts on native fish such as galaxiids, and no attempt to preserve some exotic trout-free habitats for native fish.[4]
In most situations, wholly freshwater galaxiids are unable to persist in the presence of exotic trout species, and many are now restricted to the few remaining trout-free habitats. Where these species are found in the presence of trout, the galaxiids usually consist entirely of individuals which dispersed there from an upstream trout-free population, and are not self-sustaining. Numerous localised extinctions of wholly freshwater galaxiid species (i.e. mountain galaxias) have been caused by the introduction of exotic trout species (including ongoing illegal stockings) and a number of wholly freshwater galaxiid species are threatened with extinction by exotic trout species and other exotic salmonids.[3]
Introduced salmoniids also have a negative impact on diadromous galaxiids, competing with them for food and habitat, as well as preying on them. However, the impact is not as great and they appear to be able to persist in the presence of trout.
Galaxias is a genus of small freshwater fish in the family Galaxiidae, and are frequently referred to as the galaxiids. These highly adaptable fish are typically found at temperate latitudes across the Southern Hemisphere.
Galaxiids are scaleless and somewhat tubular in body form, ranging from very slender to quite bulky. They are somewhat torpedo-shaped, with the dorsal and anal fins positioned close to the tail. They are generally small, with typical adults ranging between 4–15 cm (1.6–5.9 in) in total length, with some stocky species attaining around 25 cm (10 in). The largest, Galaxias argenteus, has been recorded at 58 cm (22.8 in; 1.9 ft), although 30–40 cm (12–16 in) is a more typical adult length.
Galaxias es un género de peces de río de la familia de los galáxidos, distribuidos por aguas fluviales de clima templado del hemisferio Sur: Oceanía, América del Sur y Sudáfrica.[1]
Son especies de agua fría, con algunas especies que pueden vivir en lagos y ríos de alta montaña, incluyendo corrientes muy pequeñas cercanas a la cabedera.[1]
Algunas especies incluyen una etapa marina en su ciclo de vida de tipo diádromo, cuando las larvas descienden río abajo hasta el mar, donde se desarrollan y retornan río arriba como juveniles, migrando hasta las altas altitudes donde pasan su vida como adultos.[2] La distribución por distintos continentes de ciertas especies se ha hipotetizado que podría deberse a la migración de los alevines cuando están en el mar de unos continentes a otros.[3]
Existen 34 especies consideradas válidas:[4]
Así como una especie extinta:
Galaxias es un género de peces de río de la familia de los galáxidos, distribuidos por aguas fluviales de clima templado del hemisferio Sur: Oceanía, América del Sur y Sudáfrica.
Galaxias on kuorekalojen lahkon melttien heimoon (Galaxiidae) kuuluva kalasuku. Suku käsittää 33 lajia. Lajit asuvat Australian ja Uuden-Seelannin vesissä. Ne ovat viileiden vesien lajeja, joista monet elävät korkealla vuoristopuroissa, mutta jotkut ovat vaelluskaloja, joiden toukat huuhtoutuvat mereen ja palaavat kudulle alavienkin maiden jokivesiin. Useimmat suvun lajit ovat pienikokoisia, mutta Galaxias argenteus voi painaa jopa kilon.[2]
Galaxias-meltit olivat tärkein luonnonvarainen Uuden-Seelannin sisävesikalaryhmä, ja toinen kahdesta tärkeimmästä Australiassa. Jokiin istutetut pohjoisen pallonpuoliskon lohikalat, kuten taimen, syövät melttejä, ja monet lajit ovat käyneet harvinaisiksi.
Galaxias on kuorekalojen lahkon melttien heimoon (Galaxiidae) kuuluva kalasuku. Suku käsittää 33 lajia. Lajit asuvat Australian ja Uuden-Seelannin vesissä. Ne ovat viileiden vesien lajeja, joista monet elävät korkealla vuoristopuroissa, mutta jotkut ovat vaelluskaloja, joiden toukat huuhtoutuvat mereen ja palaavat kudulle alavienkin maiden jokivesiin. Useimmat suvun lajit ovat pienikokoisia, mutta Galaxias argenteus voi painaa jopa kilon.
Galaxias-meltit olivat tärkein luonnonvarainen Uuden-Seelannin sisävesikalaryhmä, ja toinen kahdesta tärkeimmästä Australiassa. Jokiin istutetut pohjoisen pallonpuoliskon lohikalat, kuten taimen, syövät melttejä, ja monet lajit ovat käyneet harvinaisiksi.
Galaxias is een geslacht van straalvinnige vissen uit de familie van de snoekforellen (Galaxiidae).[1]
Galaxias is een geslacht van straalvinnige vissen uit de familie van de snoekforellen (Galaxiidae).
Galaxias é um gênero de peixe da família Galaxiidae.
Galaxias é um gênero de peixe da família Galaxiidae.
Galaxias là một chi cá nước ngọt cỡ nhỏ trong họ Galaxiidae chúng sống ở vùng Nam Bán cầu ở khu vực cận nhiệt đới nhiều loài là loài bản địa của khu vực chúng sinh sống[1]
Những loài sau đây đã được ghi nhận:[2]
Galaxias là một chi cá nước ngọt cỡ nhỏ trong họ Galaxiidae chúng sống ở vùng Nam Bán cầu ở khu vực cận nhiệt đới nhiều loài là loài bản địa của khu vực chúng sinh sống
Галаксии[1] (лат. Galaxias) — род лучепёрых рыб семейства галаксиевых (Galaxiidae).
Длина тела до 58 сантиметров (у Galaxias argenteus)[2]. Тело рыб голое, окрашено преимущественно пёстро.
Распространены в морских, прибрежных и пресных водах Новой Зеландии, Тасмании, Фолклендских островов, южной Австралии, Южной Америки, южной Африки.
У видов, обитающих в реках, характерны миграции на нерест в море. Так, взрослые особи Galaxias maculatus в январе — марте мигрируют из рек Новой Зеландии и нерестятся в эстуариях, откладывая икру на прибрежной морской растительности во время прилива. Развитие происходит так: мальки сперва обитают в море, а повзрослев мигрируют в реки. После нереста, в марте — мае, рыбы мигрируют обратно в реки. Питаются беспозвоночными.
Некоторые виды имеют местное промысловое значение.
Галаксии (лат. Galaxias) — род лучепёрых рыб семейства галаксиевых (Galaxiidae).
