The Chihuahua shiner (''Notropis chihuahua'') is a species of freshwater ray-finned fish from the family

Cyprinidae 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 verte ...

, the carps and minnows. It is found in southern Texas and northern Mexico.

Description

The Chihuahua shiner has a stout, barely compressed body which is deepest under its nape with the mouth being horizontal and situated under the rather rounded snout. It has a complete

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

; There are normally less than 10 rays in the dorsal fin and the longest ray is twice the length of the last ray and the first ray is a tiny-splinter like ray which is closely attached to the second ray, which is a well developed unbranched ray. The origin of the dorsal fin is directly over that of the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

. The

anal fin 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 se ...

has 7 soft rays. It has a thin lower lip which lacks any fleshy lobes. The

has 33-37 scales and is normally straight or it is a broad arch. Breeding males develop tubercles but these are less marked in non-breeding males and are absent in females. It has numerous large black spots widely scattered over the straw yellow back, the opercle, the area beneath the eye and the sides of snout; there is a black wedge on the caudal peduncle. The lateral line pores at front are outlined in black while the lips are yellow to pale orange as are the dorsal, caudal, and pectoral fins. It often shows a dusky stripe along the back with another stripe along the silvery flank which is dusky at the head end shading to black at the rear. It is white below with a silvery peritoneum. It grows to in

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

or total length.

Distribution

The Chihuahua shiner is found in the

Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...

drainage from near the mouth to mouth of

Rio Conchos The Río Conchos (Conchos River) is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte (known in the United States as the Rio Grande) at the town of Ojinaga, Chihuahua. Description The Rio Conchos is the main rive ...

and lower

Pecos River The Pecos River ( es, Río Pecos) originates in north-central New Mexico and flows into Texas, emptying into the Rio Grande. Its headwaters are on the eastern slope of the Sangre de Cristo mountain range in Mora County north of Pecos, New Mexico ...

in Texas. It is also found in the smaller tributaries of the Rio Conchos in

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

and

Durango Durango (), officially named Estado Libre y Soberano de Durango ( en, Free and Sovereign State of Durango; Tepehuán: ''Korian''; Nahuatl: ''Tepēhuahcān''), is one of the 31 states which make up the 32 Federal Entities of Mexico, situated in ...

in Mexico where it is abundant.

Habitat and ecology

The Chihuahua shiner is a species of small to medium sized streams where it occurs in areas with gravel to sand substrates, in clear, cool, flowing waters; it has also been recorded over rubble bottoms with some boulders, bedrock and silt. It may occur where vegetation is present. Areas where it is found are often associated with springs. It has a long spawning season which lasts from March through to early August. The females have 400 to 900 mature ova in their ovaries and there are usually more males than females with the sex ratio varying from 1.3 males: 1 female to 1.6 males:1 female. Examination of the gut contents show that these fish prey mostly on small aquatic insects. The most common intestinal parasite is a

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

. They are known to live for up to two years.

Conservation

Threats to the Chihuahua shiner include the depletion of water in the tributary creeks which are critical to the breeding and rearing of young and the introduction of exotic fish which may compete with or prey on this species.

Description

Distribution

Habitat and ecology

Conservation

References

Further reading