''Galaxias'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of small

freshwater fish Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many wa ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Galaxiidae The Galaxiidae are a family of mostly small freshwater fish in the Southern Hemisphere. The majority live in Southern Australia or New Zealand, but some are found in South Africa, southern South America, Lord Howe Island, New Caledonia, and th ...

, and are frequently referred to as the galaxiids. These highly adaptable fish are typically found at

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

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 Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

s positioned close to the tail. They are generally small, with typical adults ranging between in total length, with some stocky species attaining around . The largest, ''Galaxias argenteus'', has been recorded at , although is a more typical adult length.

Species

The 46 recognized species in this genus are: * '' Galaxias aequipinnis'' Raadik, 2014 (

East Gippsland East Gippsland is the eastern region of Gippsland, Victoria (state), Victoria, Australia covering (14%) of Victoria (Australia), Victoria. It has a population of 80,114. Australian Bureau of Statistics2006 Census Community Profile Series: Ea ...

Galaxias) * '' Galaxias anomalus'' Stokell, 1959 (Roundhead Galaxias) * '' Galaxias arcanus'' Raadik, 2014 (Riffle Galaxias) * '' Galaxias argenteus''

Gmelin Gmelin may refer to: * Karl Christian Gmelin, Carl Christian Gmelin (1762–1837), German botanist, author of ''Flora Badensis, Alsatica et confinium regionum cis- et transrhenania'' (1806) * Charles Gmelin (1872–1950), British Olympic athlete * ...

, 1789 (Giant Kōkopu) * '' Galaxias auratus'' Johnston, 1883 (Golden Galaxias) * '' Galaxias brevipinnis'' Günther, 1866 (Climbing Galaxias) * '' Galaxias brevissimus'' Raadik, 2014 (Short-tail Galaxias) * '' Galaxias cobitinis'' McDowall & Waters, 2002 (Lowland Long-jawed Galaxias) * '' Galaxias depressiceps'' McDowall & Wallis, 1996 (Flathead Galaxias) * '' Galaxias divergens'' Stokell, 1959 (Dwarf Galaxias) * '' Galaxias eldoni'' McDowall, 1997 (Eldon's Galaxias) * '' Galaxias fasciatus''

Gray Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...

, 1842 (Banded Kōkopu) * '' Galaxias fontanus'' Fulton, 1978 (Swan Galaxias) * '' Galaxias fuscus'' Mack, 1936 (Barred Galaxias) * '' Galaxias globiceps'' Eigenmann, 1928 * '' Galaxias gollumoides'' McDowall &

Chadderton Chadderton is a town in the Metropolitan Borough of Oldham, Greater Manchester, England, on the River Irk and Rochdale Canal. It is located in the foothills of the Pennines, west of Oldham, south of Rochdale and north-east of Manchester. The ...

, 1999 (Gollum Galaxias) * '' Galaxias gracilis'' McDowall, 1967 (Dwarf Inanga) * '' Galaxias gunaikurnai'' Raadik, 2014 (Shaw Galaxias) – found in the Australian Shaw Creek, Macalister River catchment, state of Victoria, Australia * '' Galaxias johnstoni'' Scott, 1936 (Clarence Galaxias) – found in the

Tasmanian Tasmania (; palawa kani: ''Lutruwita'') is an island state of Australia. It is located to the south of the Australian mainland, and is separated from it by the Bass Strait. The state encompasses the main island of Tasmania, the 26th ...

Clarence Lagoon, Derwent River catchment * '' Galaxias lanceolatus'' Raadik, 2014 (Tapered Galaxias) * '' Galaxias longifundus'' Raadik, 2014 ( West Gippsland Galaxias) * '' Galaxias macronasus'' McDowall & Waters, 2003 * '' Galaxias maculatus'' Jenyns, 1842 (Common Galaxias) * '' Galaxias mcdowalli'' Raadik, 2014 ( McDowall's Galaxias) * '' Galaxias mungadhan'' Raadik, 2014 ( Dargo Galaxias) – found in the Dargo River,

Mitchell River Mitchell River may refer to: Australia *Mitchell River (Queensland) *Mitchell River (Victoria) *Mitchell River (Western Australia) *Mann River (New South Wales) is sometimes referred to as Mitchell River. Canada *Mitchell River (Cross River) *Mit ...

catchment, Alpine and

, state of Victoria, Australia * '' Galaxias neocaledonicus'' Weber & de Beaufort, 1913 – found in

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

* '' Galaxias niger''

Andrews Andrews may refer to: Places Australia *Andrews, Queensland *Andrews, South Australia United States *Andrews, Florida (disambiguation), various places *Andrews, Indiana *Andrews, Nebraska *Andrews, North Carolina *Andrews, Oregon *Andrews, South ...

, 1985 (Black Galaxias) * '' Galaxias occidentalis'' Ogilby, 1899 (Western Galaxias) * '' Galaxias olidus'' Günther, 1866 (Mountain Galaxias) * '' Galaxias oliros'' Raadik, 2014 (Obscure Galaxias) * '' Galaxias ornatus'' Castelnau, 1873 (Ornate Galaxias) * '' Galaxias parvus'' Frankenberg, 1968 (Small Pedder Galaxias) – found in the Tasmanian

Lake Pedder Lake Pedder, once a glacial outwash lake, is a man-made impoundment and diversion lake located in South West Tasmania, Australia. In addition to its natural catchment from the Frankland Range, the lake is formed by the 1972 damming of the ...

* '' Galaxias paucispondylus'' Stokell, 1938 ( Alpine Galaxias) – found in the

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) are a mountain range extending along much of the length of New Zealand, New Zealand's South Island, reaching its greatest elevations near the range's western side. The n ...

of New Zealand * '' Galaxias pedderensis'' Frankenberg, 1968 ( Pedder Galaxias) – found in the Tasmanian

* '' Galaxias platei'' Steindachner, 1898 * '' Galaxias postvectis'' F. E. Clarke, 1899 (Short-jaw Kōkopu) * '' Galaxias prognathus'' Stokell, 1940 (Long-jaw Galaxias) * '' Galaxias pullus'' McDowall, 1997 (Dusky Galaxias) * '' Galaxias rostratus'' Klunzinger, 1872 (Flathead Galaxias) * '' Galaxias supremus'' Raadik, 2014 (Kosciuszko Galaxias) – found in the Australian Kościuszko National Park (pronounced: /ˌkɒziˈʌskoʊ/, KOZ-ee-USK-oh) in

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. * '' Galaxias tantangara'' Raadik, 2014 (Stocky Galaxias) – endemic to the Australian Tantangara Creek in the upper

Murrumbidgee River The Murrumbidgee River () is a major tributary of the Murray River within the Murray–Darling basin and the second longest river in Australia. It flows through the Australian state of New South Wales and the Australian Capital Territory, desce ...

system of the Kościuszko National Park * '' Galaxias tanycephalus'' Fulton, 1978 (Saddled Galaxias) * '' Galaxias terenasus'' Raadik, 2014 (Roundsnout Galaxias) * '' Galaxias truttaceus''

Valenciennes Valenciennes (, also , , ; ; or ; ) is a communes of France, commune in the Nord (French department), Nord Departments of France, department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced ...

, 1846 (Spotted Galaxias) * '' Galaxias vulgaris'' Stokell, 1949 (Common River Galaxias) * '' Galaxias zebratus'' Castelnau, 1861 (

Cape A cape is a clothing accessory or a sleeveless outer garment of any length that hangs loosely and connects either at the neck or shoulders. They usually cover the back, shoulders, and arms. They come in a variety of styles and have been used th ...

Galaxias) – endemic to South Africa's

Western Cape The Western Cape ( ; , ) is a provinces of South Africa, province of South Africa, situated on the south-western coast of the country. It is the List of South African provinces by area, fourth largest of the nine provinces with an area of , an ...

Distribution

Galaxiids are restricted to the Southern Hemisphere, and generally only occur in temperate latitudes. Only one species is known from

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

habitats. Galaxiids are the dominant group of native freshwater fish in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, and, along with the Percichthyidae, one of two dominant groups of native freshwater fish in southeastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. 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. One species ('' G. neocaledonicus'') is endemic to the

Habitat

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 Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousa ...

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.

Threats

Wholly freshwater galaxiids are gravely threatened by exotic

salmonid Salmonidae (, ) is a family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic a ...

species, particularly exotic

trout Trout (: trout) is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of which are members of the subfamily Salmoninae in the ...

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.Biodiversity, Alien trout, and the "So what" attitude
/ref> 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. 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.

References

External links