The Cape galaxias (''Galaxias zebratus'') is a species of freshwater fish of 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 ...

. It is a small fish, rarely larger than 6 cm, that inhabits clear streams, rivers and ponds of South Africa. It shares the same habitat as imported

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 ...

and

bass Bass or Basses may refer to: Fish * Bass (fish), various saltwater and freshwater species Wood * Bass or basswood, the wood of the tilia americana tree Music * Bass (sound), describing low-frequency sound or one of several instruments in th ...

species and has been identified as prey. The numbers of this relatively delicate fish have declined around

Cape Town Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest ...

. Although in South Africa it was at one time classified as

near threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...

, in Australia species of the same genus were driven to

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

by competing salmonids and other

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

of fish. It is now classified as " Data Deficient" on the grounds that the taxonomic status of the

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

is unclear.

Description

The Cape galaxias is a small slender fish with a cylindrical body and no scales. It has a single dorsal fin with 9 to 13 soft rays set well back on the body and just above the anal fin which has a similar number of rays. It is silvery in colour and the internal organs can be seen through the skin.

Distribution and habitat

Genus '' Galaxias'' is restricted to the Southern Hemisphere and the Cape galaxias is unique because it is the only species of the genus found in the African continent. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

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 ...

region in South Africa and the first specimen caught by scientists was captured in the

Cape Flats The Cape Flats () is an expansive, low-lying, flat area situated to the southeast of the central business district of Cape Town. The Cape Flats is also the name of an administrative region of the City of Cape Town, which lies within the larger geo ...

area in 1861. For a long time it was believed that the distribution of this fish species was restricted to the

, within an area ranging between the Keurbooms River and the Olifants River. However, since 1995 it has been also found in the

Krom River Krom River or Kromme River () is a river in the Eastern Cape Province in South Africa. The river flows into the Indian Ocean through an estuary on the north side of Kouga Local Municipality, St Francis Bay, west of Port Elizabeth. The Krom river ...

as well as in the Gamtoos River system of the

Eastern Cape The Eastern Cape ( ; ) is one of the nine provinces of South Africa. Its capital is Bhisho, and its largest city is Gqeberha (Port Elizabeth). Due to its climate and nineteenth-century towns, it is a common location for tourists. It is also kno ...

.Freshwater Ichthyology - The Cape galaxias Galaxias zebratus
/ref> Some of the taxa in the complex are found in clear mountain streams with low dissolved mineral levels but others seem to prefer lowland streams that can be turbid and have high levels of dissolved minerals.

References

External links

{{Taxonbar, from=Q44199 Galaxias Taxa named by François-Louis Laporte, comte de Castelnau Freshwater fish of South Africa Fish described in 1861