Threatened fishes of the world: Barbus haasi (Mertens 1925) (Cyprinidae)

Abstract

barbel not reaching the rear edge of the eye. Last unbranched ray of the dorsal fin with small denticles. Anal fin is long and caudal peduncle is short and high. Body presents dark blotches. Part of caudal, anal and pelvic fins are red. Drawing by Rafael Miranda. Distribution: Most headwater streams of the Ebro River Basin and North Mediterranean rivers of the Iberian Peninsula. Abundance: Restricted to headwaters and occasionally in middle reaches of streams, scarce where present. Habitat and ecology: This benthonic species prefers upper reaches of rivers, with high flow and clear, cold waters. Barbus haasi occurs in rocky and vegetated areas and feeds on macroinvertebrates (mainly Chironomidae, Ephemeroptera and Trichoptera). Reproduction: The spawning period extends throughout April and June, related to periods of high stream flow. Fecundity ranges from 2000 to 7000 eggs per female. The males have an early maturity (one year) and grow more slowly than females. The females live for 8 years while the males only live for 7 years. The females have multiple spawning, releasing two to five egg batches depending on their size, such that largest females spawn more batches than the small ones (Aparicio & Sostoa 1998). Threats: The species is threatened by invasive alien fish species (mainly piscivores) and habitat loss due to water abstraction, construction of small dams, stream desiccation, etc. Anthropogenic water pollution is another important disturbance factor. This endemic species of the Iberian Peninsula is currently in rapid decline because the above noted impacts are intensified by the characteristic irregularity of the Mediterranean rivers. Conservation action: None. Conservation recommendations: Waste water and water pollution control and treatment. Correction of the impact of stream regulation by water releases to simulate natural flow patterns. Prevent alien fish species introductions and eradication of the existing alien species which impact on B. haasi. Habitat protection and control of invasive alien fish species are the main actions necessary to prevent the further decline of Barbus haasi. Remarks: There has been some controversy with regard to the systematic position of