The climbing galaxias or kōaro (''Galaxias brevipinnis'') is a fish of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Galaxiidae found in

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

, and nearby islands. The name climbing galaxias is used in Australia, and koaro or kōaro in New Zealand. Further vernacular names include short-finned galaxias, broad-finned galaxias, Cox's mountain galaxias, and Pieman galaxias.

Appearance

Adult koaro (Galaxias brevipinnis) from the Momona Stream, Taranaki

The climbing galaxias is unlikely to be confused with the other diadromous

whitebait Whitebait is a collective term for the immature fry of fish, typically between long. Such young fish often travel together in schools along coasts, and move into estuaries and sometimes up rivers where they can be easily caught using fine-m ...

species because of its shape. It is elongated and slender, shaped almost like a tube. The sides and back are covered in a variable pattern of golden blotches and bands that gleam and glitter in the sun, making the climbing galaxias an attractive fish. Their maximum size is around 29 cm, but they commonly reach 16–18 cm.

Lifestyle

These fish live a basically

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning " ...

lifestyle and in most respects behave like the common galaxias, a closely related galaxiid. They inhabit mainly clear streams, often deeply shaded and relatively fast-flowing, although they sometimes occur in lakes, particularly in Tasmania. Climbing galaxias also have the ability to penetrate well inland in many river systems, thus have a more widespread distribution than the other whitebait species. A major distinguishing feature of this species is its ability to climb up very steep surfaces such as

waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in several ...

s, wet rocks, and the sluices of dams using its broad and downward facing pectoral and pelvic fins. Even juveniles of the species are capable of climbing up and over the sides of buckets after being trapped in whitebait nets. Climbing ability is not unique among galaxias species, but it reaches its greatest expression in the climbing galaxias, which have special features that enhance their climbing abilities. The downward orientation of their fins and the strong, backward-facing ridges on the front part of their fins possibly contribute to this ability. Climbing galaxias once formed large populations in some lakes. It once roamed New Zealand's

Lake Taupō Lake Taupō (also spelled Taupo; mi, Taupō-nui-a-Tia or ) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's n ...

in huge shoals and was caught in huge numbers by Maori people using specialised nets. Introduced rainbow trout has now virtually eradicated the species from Lake Taupō. Similarly, the introduction of brown trout eradicated a climbing galaxias population from Lake Tali Karng in Victoria, Australia (Cadwallader, 1996).

Lifecycle

''G. brevipinnis'' eggs are believed to be washed downstream to the

sea The sea, connected as the world ocean or simply the ocean, is the body of salty water that covers approximately 71% of the Earth's surface. The word sea is also used to denote second-order sections of the sea, such as the Mediterranean Sea, ...

, where the young live for about six months before returning to

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does incl ...

as part of the large, mixed-species

schools A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes compulsor ...

known as whitebait. They were once part of a commercial whitebait fishery in Tasmania, but now fishing for them has been restricted to recreational anglers with significant restrictions on allowable tackle and methods. Land-locked populations have a similar lifestyle except the young spend the first part of their lives in inland

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s and backwaters.

Diet

These fish are generalised

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other s ...

s of

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

s, including aquatic and terrestrial

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

mayfly Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the orde ...

and

caddisfly The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e, and

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

Distribution

Their distribution extends to coastal streams in southeastern Australia from

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

and

Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest o ...

, through coastal Victoria including

Wilsons Promontory Wilsons Promontory, is a peninsula that forms the southernmost part of the Australian mainland, located in the state of Victoria. South Point at is the southernmost tip of Wilsons Promontory and hence of mainland Australia. Located at nea ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, Flinders and King Islands, and north along the

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

coast to around

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mounta ...

, as well as

including the Chatham,

Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The most populous urban area in the country and the fifth largest city in Oceania, Auckland has an urban population of about I ...

and Campbell Islands. Their climbing ability enables them to inhabit headwaters of streams that introduced species, such as trout, cannot reach.

References

External links

Climbing Galaxias at Wilsons Promontory video on Youtube

Climbing Galaxias on Flinders Island video on Youtube

Galaxias brevipinnis and Euastacus crayfish video on Youtube
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Climbing galaxias
Native Fish Australia

TerraNature, Auckland 2010 {{DEFAULTSORT:Climbing galaxias climbing galaxias Freshwater fish of New Zealand Freshwater fish of Australia Fauna of the Auckland Islands Taxa named by Albert Günther climbing galaxias