Siphateles bicolor snyderi

Owens tui chub

Family: Leuciscidae · Class: Actinopterygii · Order: Cypriniformes

Conservation status: SE · Endangered · G4T1 S1

The Owens tui chub (Siphateles bicolor snyderi) is a small cyprinid fish endemic to the Owens Valley of California. Adults typically reach 150 to 250 mm (6 to 10 inches) in total length, with a deep, laterally compressed body characteristic of the tui chub complex. The species exhibits a dusky olive to bronze coloration on the dorsal surface, grading to silvery-white on the ventral side. A distinctive dark lateral stripe extends from the snout through the eye to the caudal peduncle. The mouth is subterminal with small pharyngeal teeth adapted for processing algae and small invertebrates. Historically, the Owens tui chub was distributed throughout the Owens River system in Inyo and Mono counties, California. The subspecies occupied the mainstem Owens River, associated sloughs, and several natural lakes including Owens Lake before its desiccation. Currently, the population is restricted to a few isolated locations within the Owens Valley, representing a dramatic reduction from its historical range. The U.S. Fish and Wildlife Service listed the subspecies as endangered in 1985, and California Department of Fish and Wildlife notes that it is listed by both the state of California and USFWS under the synonym Gila bicolor snyderi. The species inhabits slow-moving or standing waters with abundant aquatic vegetation and soft substrates. Preferred habitats include backwater sloughs, irrigation channels, and remnant wetland areas with water temperatures ranging from 10 to 25 degrees Celsius (50 to 77 degrees Fahrenheit). The subspecies tolerates moderate salinity levels but requires permanent water sources with adequate dissolved oxygen. Elevation range extends from approximately 1,200 to 1,300 meters (3,900 to 4,300 feet) above sea level. Owens tui chubs are omnivorous, feeding on algae, aquatic insects, small crustaceans, and plant material. Spawning occurs from April through June when water temperatures reach 15 to 20 degrees Celsius (59 to 68 degrees Fahrenheit). Females deposit adhesive eggs on submerged vegetation or gravel substrates, with clutch sizes ranging from 1,000 to 3,000 eggs. Juveniles mature at approximately 18 months of age. The species exhibits schooling behavior and can form dense aggregations in suitable habitat areas. The primary threats to Owens tui chub survival include habitat loss due to water diversions, competition and predation from introduced species, and habitat degradation from cattle grazing and water management practices. The Owens River system has been extensively modified for water export to Los Angeles, resulting in dewatered reaches and altered flow regimes. Non-native species such as largemouth bass, brown trout, and mosquitofish pose significant threats through predation and resource competition. Recovery efforts focus on habitat restoration, population monitoring, and the establishment of refuge populations in protected habitats. Current population estimates suggest fewer than 1,000 individuals remain in the wild, making this one of California's most imperiled freshwater fish subspecies.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.