Siphateles bicolor ssp. 12

Eagle Lake Tui Chub

Family: Leuciscidae · Class: Actinopterygii · Order: Cypriniformes

Conservation status: G4T1T2 S1S2

The Eagle Lake Tui Chub is a freshwater fish endemic to Eagle Lake in northeastern California. This subspecies belongs to the cyprinid family and represents one of several isolated tui chub populations throughout the western United States. Adults typically reach lengths of 100-200 mm (4-8 inches), with a robust, laterally compressed body. The species displays a silvery coloration with darker dorsal surfaces and lighter ventral areas. Like other tui chub subspecies, it possesses a subterminal mouth adapted for bottom feeding and lacks barbels. The Eagle Lake Tui Chub is restricted to Eagle Lake, located in Lassen County, California, within the Northern Lahontan Basin. This large, alkaline lake sits at an elevation of approximately 1,524 meters (5,000 feet) in the northeastern portion of the state. The species' range is entirely contained within this single water body, making it one of the most geographically restricted fish subspecies in California. Eagle Lake is characterized by highly alkaline waters with elevated pH levels, similar to other closed-basin lakes in the Great Basin region. The lake supports a unique aquatic ecosystem adapted to these extreme chemical conditions. Water temperatures vary seasonally, with the lake typically freezing in winter and warming considerably during summer months. The substrate consists primarily of sand, gravel, and organic matter, providing foraging areas for benthic invertebrates that serve as prey for the tui chub. Eagle Lake Tui Chub are opportunistic omnivores, feeding on aquatic insects, crustaceans, algae, and detritus. Their diet varies seasonally based on prey availability, with increased consumption of emergent insects during warmer months. Spawning occurs in spring and early summer when water temperatures rise, with adults moving to shallow areas along the shoreline. Females deposit adhesive eggs on submerged vegetation and rocky substrates. The species exhibits relatively long lifespans compared to other cyprinids, potentially reaching 8-10 years in the stable lake environment. The subspecies carries a global rank of G4T1T2, indicating that while the broader species (Siphateles bicolor) is relatively secure, this particular subspecies faces significant conservation concerns. The S1S2 state rank reflects its critically imperiled to imperiled status within California. Primary threats include water level fluctuations due to drought and water management, potential introduction of non-native fish species, and climate change impacts on the lake's unique chemistry. The subspecies' survival depends entirely on maintaining the ecological integrity of Eagle Lake, as no alternative habitat exists for this endemic population. Long-term monitoring of water quality, fish populations, and potential invasive species is essential for the subspecies' continued persistence. Scientific documentation for this subspecies remains limited compared to other tui chub populations. If you have additional verified information about this species' biology, distribution, or ecology, please contact us to help improve this species account.

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