Siphateles bicolor pectinifer

Lahontan Lake Tui Chub

Family: Leuciscidae · Class: Actinopterygii · Order: Cypriniformes

Conservation status: G4T3 S1S2

The Lahontan Lake Tui Chub is a subspecies of tui chub endemic to a small number of lakes in the California-Nevada region. This freshwater fish represents one of several geographically isolated subspecies of Siphateles bicolor that have evolved in distinct Great Basin watersheds. Adults typically measure 100 to 200 mm (4 to 8 inches) in total length, with a robust, laterally compressed body characteristic of the tui chub complex. The species displays the typical cyprinid body form with a terminal mouth, relatively large scales, and a deeply forked caudal fin. Coloration varies from olive-brown to silvery, with darker pigmentation on the dorsal surface and lighter ventral coloration. Historically, the Lahontan Lake Tui Chub occurred in multiple lake systems within the Lahontan Basin, which spans portions of California, Nevada, and Oregon. The current distribution is severely restricted compared to historical ranges, with populations persisting in only a few isolated lake systems. According to NatureServe, this subspecies has a small range that includes a few lakes in the California-Nevada border region. The fragmented nature of remaining populations reflects the broader pattern of habitat loss and degradation affecting Great Basin aquatic systems. Lahontan Lake Tui Chubs inhabit lentic environments, primarily occurring in lakes, reservoirs, and associated wetland systems. The species demonstrates tolerance for a range of water conditions, including variable salinity levels and seasonal temperature fluctuations typical of Great Basin lake systems. They typically occupy nearshore areas with submerged vegetation and prefer areas with moderate depths ranging from shallow littoral zones to deeper pelagic waters. The subspecies shows adaptation to the alkaline conditions common in many Great Basin lakes. As omnivorous feeders, Lahontan Lake Tui Chubs consume a varied diet including aquatic invertebrates, algae, detritus, and small fish when available. Spawning typically occurs in spring and early summer when water temperatures increase, with adults moving to shallow areas with suitable substrate for egg deposition. Females scatter adhesive eggs over vegetation or rocky substrates, and no parental care is provided after spawning. The species exhibits schooling behavior, particularly during feeding and spawning periods. The Lahontan Lake Tui Chub faces significant conservation challenges, reflected in its Global/State Rank of G4T3 S1S2, indicating it is vulnerable globally and critically imperiled to imperiled in California. According to NatureServe, the subspecies confronts numerous threats including exotic species introductions, habitat modification, and water diversions that affect lake levels and water quality. Competition and hybridization with introduced fish species pose particular risks to genetic integrity. Climate change compounds these pressures through altered precipitation patterns and increased temperatures affecting Great Basin aquatic systems. The restricted range and small population size make this subspecies particularly vulnerable to environmental fluctuations and catastrophic events. Conservation efforts require careful management of remaining lake habitats and control of invasive species to ensure long-term persistence.

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