Zingel asper (Linnaeus, 1758)
Rhone streber

Family:  Percidae (Perches), subfamily: Luciopercinae
Max. size:  22 cm TL (male/unsexed); max.weight: 100.0 g
Environment:  demersal; freshwater
Distribution:  Europe: Rhône drainage, except Lake Geneva basin (France, Switzerland). Originaly widespread, but following habitat alterations, distribution is now much fragmented and restricted. Main subsisting populations in the middle Doubs (France, Switzerland) and Durance and Ardeche (southern France).
Diagnosis:  Dorsal spines (total): 8-13; Dorsal soft rays (total): 10-14; Anal spines: 1-3; Anal soft rays: 8-12; Vertebrae: 43-45. The presence of 57-65 + 3-6 scales along lateral line distinguishes uniquely this species from its congeners. Can be further separated from other species by the combination of the following characters: first dorsal fin with 8-9 spines; second dorsal fin with 1-2 simple and 9-12½ branched rays; scaleless cheeks (Ref. 59043). Caudal fin with 17 soft rays (Ref. 40476).
Biology:  A short-lived species reported to live in fast-flowing rivers with a gravel substrate (Ref. 30578). Occurs in main course of rivers and large streams and in riffles. Found on stone bottom (Ref. 59043). Lurks on the bottom during the day and comes out for crepuscular feeding (Ref. 11941). Feeds on aquatic invertebrates. Larvae feed on plankton under surface, then at about 2.5 cm SL, they move to benthic habitats. Attains first sexual maturity at 2-4 years of age. Spawns in deeper parts of riffles. Deposits on gravel strongly adhesive eggs, 2.2 mm in diameter, which hatch in about 14 days at 13° C (Ref. 59043). Threatened due to habitat destruction and pollution (Ref. 26100).
IUCN Red List Status: Critically Endangered (CR); Date assessed: 31 January 2006 (B2ab(iii)) Ref. (130435)
Threat to humans:  harmless


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