Lepidomeda vittata

Tibbets et al. (2001) examined mtDNA and allozyme variation in remaining populations of L. vittata and found that "genetic diversity was low, but population structure was high because of partitioning of genotypes among samples. Similarity of genotypes suggest[s] current populations are relics from a single, large population that was once continuously distributed throughout the [Lower Colorado River] drainage."

Small range in north-flowing tributaries of the Little Colorado River in eastern Arizona; has declined due to habitat alteration and loss from human activities and drought, introduction and spread of exotic predatory and competitive fishes, and chemical manipulation of fish populations in native streams.

This species formerly occurred throughout the upper sections of the Little Colorado River system in eastern Arizona, (Minckley 1973, Lee et al. 1980, Page and Burr 2011). Currently the range of the species is confined to disjunct locations within the East Clear Creek Watershed, Chevelon Creek, the upper Little Colorado River (including Nutrioso and Rudd Creeks), and Silver Creek (USFWS 2008). Recent surveys did not locate this species in Silver Creek, and very few were found in Nutrioso and Rudd creeks; this species is considered rare in the East Clear Creek watershed, Chevelon Creek, and the mainstem Little Colorado River (USFWS, Arizona Ecological Services Field Office; USFWS 2008).

This species is represented by several (not more than 10) extant occurrences (subpopulations). Number of locations (as defined by IUCN) may not exceed five.

Decline has been due to habitat alteration and loss, introduction and spread of exotic predatory and competitive animals (Blinn et al. 1993), and chemical manipulation of fish populations in native streams (USFWS 1987, Sweetser et al. 2002).

Long-term drought and current and planned water acquisitions are limiting the amount of water available for the fish. Additionally, non-native fishes (rainbow trout, green sunfish) and crayfish compete with spinedace and are predators upon them (USFWS, Arizona Ecological Services Field Office).

Habitat loss and fragmentation continue to be serious threats to the fish's existence. Human activities, such as riparian modification and destruction, urban growth, mining, timber harvest, road construction, livestock grazing, and other watershed disturbances (e.g., road construction and maintenance, recreational development and usage, fire management, and inter-basin water diversions) have also had detrimental effects to spinedace habitat. These activities have affected watershed function, runoff patterns, peak flows, seasonal flows, riparian vegetation, wet meadow functions, bank erosion, siltation, and water quality. Introduction of non-native trout, baitfish, and crayfish at recreational lakes and reservoirs have increased competition for available resources and predation on spinedace. In addition, extended drought cycles and increased development of groundwater resources are impacting habitat for spinedace within their historical range. It has become more difficult to find spinedace because drought conditions have reduced available habitat. Source: USFWS (2009).

USFWS (2008) stated that "continued invasion of non-native aquatic species into spinedace habitat and the on-going and future reductions in surface water (due to both drought and surface and groundwater pumping) are threats that are increasing in magnitude, extend to existing spinedace populations, and are contributing factors to the spinedace's continuing decline throughout its range. Within the foreseeable future (50 years) the complete loss of baseflow to the area that supports the largest population of spinedace has been predicted by two different hydrologic models based upon current groundwater pumping; we expect the rate of groundwater pumping to increase in the future as the human population in the area increases. There are very few habitats within the range of the species that are currently able to be occupied due to lack of water or presence of multiple predators, so at this time, recovery options are limited. Areas that are currently able to support spinedace are relatively small, fragmented habitats that frequently have no connection to other habitats due to lack of water."