''Squalius aradensis'' is a

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in 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 ...

Cyprinidae, growing to SL. It is

endemic Endemism is the state of a species being found 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 found else ...

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

where it is found in only three river basins:

Arade The Arade () is a river located in the region of the Algarve, southern Portugal. the river's course takes it through the municipalities of Silves, Lagoa and Portimão. The source of the river lies to the southwest of the Serra do Caldeirão mou ...

, Algibre, and Bordeira basins. It is threatened by water extraction, drought, and introduction of exotic fish species. ''Squalius aradensis'' is an ubiquitous species which inhabits small to medium-sized streams with Mediterranean water regime. It may be restricted to very small pools during summer. It breeds in shallow riffle habitats in fast-flowing water.

References

Squalius Endemic fauna of Portugal Freshwater fish of Europe Fish described in 1998 Taxonomy articles created by Polbot {{Leuciscinae-stub