Southern Iberian chub

Squalius pyrenaicus is endemic to the catchment of the Tagus river in Spain and Portugal. It is found in a wide variety of rivers and stream at varying altitudes and different currents, avoiding the wide, deep lowland stretches of rivers. Many of the streams it inhabits partially dry up in the summer, when it uses relict pools as refuges.

Squalius pyrenaicus belongs to the genus Squalius. This name was proposed by the French bioogist Charles Lucien Bonaparte in 1837 for a subgenus of the genus Leuciscus for the Italian chub (Squalius cephalus), inserting an additional "i" to prevent homonymy with the spurdog genus Squalus. In classical Latin the chub and the spurdog were homonyms as squalus. An alternative explanation was that the name is a latinisation of squaglio, a vernacular name for the Italian chub in Rome and its environs. The specific name, pyrenaicus, means "of the Pyrenees", although this species was described from Portugal.