Agosia chrysogaster sp 1

Yaqui Longfin Dace
Conservation status
Near Threatened  (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Agosia
Species:	A.  chrysogaster species 1
Binomial name
Agosia chrysogaster species 1 Baird and Girard, 1853

The Yaqui longfin dace, official name Agosia chrysogaster sp. 1, is a small fish of the American Southwest and northern Mexico.

Description

The Yaqui longfin dace is similar to the Gila longfin dace, having the same average length of 3.5 inches and similar colors. Its silvery gray and olive color pattern is similar to the Gila dace, however the Yaqui 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, and both are fusiform. They also have a triangular dorsal fin with the absence of a dark spot.^{[1][2] [3][4][5]}

Distribution

In Arizona, the Yaqui dace only occurs in the southeast, in Cochise County. However, it is also found in northern Mexico, as the fish migrate south to warmer waters during the winter months. The Yaqui dace was re-introduced into the Yaqui River on the San Bernardino Wildlife Refuge and the Leslie Creek Wildlife Refuge including West Turkey Creek at Rucker Canyon. The Yaqui dace has the same elevation restrictions as the Gila dace, ranging only below 1484 meters, with records of up to 2030 meters. They are found in Desert Scrub to Madrean Oak Woodlands.

Habitat

The habitat of the Yaqui dace is identical to that of the Gila dace, and it has the same wide range of water temperature preferences, being found from low and hot desert streams to mountain brooks with extremely cold water. 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 23.89 degrees Celsius, with a water depth average of 0.18 meters. During water shortages, they seek refuge in algae and detritus mats of wetland habitats.

Reproduction

Yaqui dace usually spawn in the spring from December to July, but extend the season into to September in low desert habitats. They reach sexual maturity within the first year of birth, 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 between fecundity and fish length, and it is suggested that the same correlation exists between male length and mating success.

Biology

Sediment discharge in river bottoms occurs during flooding seasons, and will cause 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 invertebrates, zooplankton, and other forms of algae as circumstances allow. The life span of the Yaqui dace is three years and they are very susceptible to predation, more so than its relative the Gila dace. Crayfish and other introduced species feed on the Yaqui dace.^[6]

Notes

External links

• ITIS "Agosia chrysogaster"
• Fishbase "Agosia chrysogaster"