The Borax Lake chub (''Siphateles boraxobius'') is a rare

cyprinid Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest ver ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

found only in outflows and pools around Borax Lake, a small lake of the Alvord basin,

Harney County, Oregon Harney County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 7,495, making it the sixth-least populous county in Oregon. The county seat is Burns. Established in 1889, the county is named in h ...

. This species typically reaches only in length, although some are as long as . The back is generally a dark olive green, while the sides are silvery, with a dark line extending from gill cover to tail, and a scattering of dark

melanophore Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in cont ...

s. The fins are colorless, with more melanophores on the rays of the dorsal fin and tail, as well as on the first four rays of the pectoral fins. Similar in many ways to the Alvord chub, the Borax Lake species has a longer, wider, and deeper head, and larger eyes, and the

caudal peduncle Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

is more slender. Boraxlake

The Borax Lake chub eats a variety of foods, including midge larvae, diatoms, copepods,

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typi ...

s, and terrestrial insects. Its preferred mode of feeding is to root around in the bottom, but it will go after floating material or feed from the surface if necessary. This species is the sole fish inhabiting the Borax Lake waters. While parts of the lake itself can, at times, rise to about fed from thermal springs, the average temperature ranges between . The fish avoid the warmest water, favoring lake's outflows. Its continued existence was threatened by geothermal energy development near the lake, which dried up part of the chub's habitat. However, in 2000 the Steens Mountain Cooperative Management and Protection Act put the area around the lake off-limits to geothermal exploration and mining.

References

* Listed as Vulnerable (VU D2 v3.1) * * William F. Sigler and John W. Sigler, ''Fishes of the Great Basin'' (Reno: University of Nevada Press, 1987), pp. 170–173 * Borax lake panorama

{{Taxonbar, from=Q3756729 Borax Lake Siphateles Endemic fauna of Oregon Fish of the Western United States Freshwater fish of the United States Natural history of Oregon Fish described in 1980 ESA endangered species