The Yaqui longfin dace is a small fish of the

American Southwest The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, N ...

and

northern Mexico Northern Mexico ( es, el Norte de México ), commonly referred as , is an informal term for the northern cultural and geographical area in Mexico. Depending on the source, it contains some or all of the states of Baja California, Baja California ...

, and considered a form of the longfin dace. It is often referred to as ''Agosia chrysogaster'' sp 1.

Description

The Yaqui longfin dace is similar to the

Gila longfin dace The Gila longfin dace (''Agosia chrysogaster chrysogaster'') is an subspecies of the longfin dace found in Arizona. It is considered the nominate subspecies of the longfin dace. Description The only other form of fish closely related to Gila ...

, but differs slightly in body shape and relative placement of fins, with this form being generally smaller, and less sexually dimorphic, and having longer pre- and postdorsal body lengths.Hendrickson, Dean A. 1987. “Geographic Variation in Morphology of ''Agosia chrysogaster'', a Sonoran Desert Cyprinid Fish.” Ph.D., Tempe, Arizona: Arizona State University. https://hdl.handle.net/2152/81257. http://dx.doi.org/10.26153/tsw/8270. Tuberculation also appears to differ between the two forms. Its silvery gray and olive color pattern is similar to the Gila longfin dace, however the Yaqui longfin dace can sometimes have golden speckles along its body. The lower abdomen can be white as well. The Gila and Yaqui longfin daces both have black spots on their

caudal fins Fins are distinctive anatomical features composed of bony spine (zoology), spines or Ray (fish fin anatomy), 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 bon ...

, and both are fusiform. They also have a triangular

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

with the absence of a dark spot.

Distribution

In Arizona, the Yaqui longfin dace only occurs in the southeast, in

Cochise County Cochise County () is a county in the southeastern corner of the U.S. state of Arizona. It is named after the Native American chief Cochise. The population was 125,447 at the 2020 census. The county seat is Bisbee and the most populous city is ...

(in both the endorheic Sulphur Springs (Willcox Playa) and Río Yaqui drainages). However, it is also found in northern Mexico, in the Yaqui, Sonora, Mayo, Fuerte and Sinaloa River Basins of Sonora and Sinaloa. The Yaqui longfin dace was re-introduced into the

Yaqui River The Yaqui River (Río Yaqui in Spanish) (Hiak Vatwe in the Yaqui or Yoreme language) is a river in the state of Sonora in northwestern Mexico. It was formerly known as the Rio del Norte. Being the largest river system in the state of Sonora, the ...

on the San Bernardino Wildlife Refuge and the Leslie Creek Wildlife Refuge including West Turkey Creek at

Rucker Canyon Rucker Canyon is a major canyon draining the western central-south of the Chiricahua Mountains, the central landform of the eastern third of Cochise County, Arizona's extreme southeast, bordering southwest New Mexico. It is famous for historic Ca ...

. The Yaqui longfin dace has the same elevation restrictions as the Gila longfin dace, ranging only below 1484 m, with records of up to 2030 m. They are found in

desert scrub Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this ...

to Madrean oak woodlands.

Habitat

The habitat of the Yaqui longfin dace is similar to that of the Gila longfin dace, and it ranges from low and hot desert streams to about 1600 m elevation.Hendrickson, Dean A., W. L. Minckley, Robert R. Miller, Darrell J. Siebert, and Patricia Haddock Minckley. 1980. “Fishes of the Río Yaqui Basin, México and United States.” ''Journal of the Arizona-Nevada Academy of Science'' 15 (3): 65–106. http://www.jstor.org/stable/40025038. They prefer brooks and streams that have sandy or gravely bottoms, typically with overhanging banks protecting them from predator or human observation. Their average water temperature preference is 23.9°, with a water depth average of 0.18 m. During water shortages, they seek refuge in algae and detritus mats of wetland habitats.

Reproduction

Yaqui longfin dace usually spawn in the spring from December to July, but extend the season into September in low desert habitats. They reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...

within their first year, and create depressions in the sand to hide their eggs. This helps them provide a safe place for development, allowing minimal disturbance from other species or predators. Studies have shown a

positive correlation In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistic ...

between fecundity and fish length, and the same correlation is suggested to exist between male length and mating success.

Biology

Sediment discharge in river bottoms occurs during flooding seasons, and causes the dace to swim directly into the currents avoiding the spraying of sediment into the gills. If drought occurs, the fish also seek refuge in wetland areas such as algae mats. They prevent desiccation by hiding under logs and stones. The wetlands provide detritus, a nutrient that these fish primarily eat, as the fish are omnivorous and opportunistic feeders. They can also feed on

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, and other forms of

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

as circumstances allow. The lifespan of the Yaqui longfin dace is three years and they are very susceptible to predation, more so than the Gila longfin dace. Crayfish and other introduced species feed on the Yaqui longfin dace."Animal Abstract: ''Agosia chrysogaster sp 1''"
Heritage Data Management System, Arizona Game and Fish Department

References

{{Taxonbar, from=Q4693603 Cyprinid fish of North America Taxa named by Spencer Fullerton Baird Taxa named by Charles Frédéric Girard Undescribed vertebrate species