The loach minnow (''Rhinichthys cobitis'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

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 li ...

. It is a member of the

carp Carp are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. While carp is consumed in many parts of the world, they are generally considered an invasive species in parts of ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

(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 ...

) of

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Cypriniformes Cypriniformes is an order of ray-finned fish, including the carps, minnows, loaches, and relatives. Cypriniformes is an Order within the Superorder Ostariophysi consisting of "Carp-like" Ostariophysins. This order contains 11-12 families, ...

. It occurs in streams and small rivers throughout the

Gila River The Gila River (; O'odham ima Keli Akimel or simply Akimel, Quechan: Haa Siʼil, Maricopa language: Xiil) is a tributary of the Colorado River flowing through New Mexico and Arizona in the United States. The river drains an arid watershed of n ...

and San Pedro River systems in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

, and

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

; it is now considered extinct in Mexico.

Description

Loach minnow has an elongated, compressed body with its size rarely exceeding in length.Minckley, W.L. 1973. Fishes of Arizona. Arizona Game and Fish Department, Phoenix. pp. 133-135. This species have an olivaceous body, highly blotched with darker pigment. They have dirty-white spots before and behind base of dorsal fin, and on lower and upper sides base of caudal. Breeding males have vivid red-orange markings on bases of fins, body, and lower head. Breeding females become yellow on their fin and lower body. The loach minnow has whitish spots that are present on the origin and insertion of the dorsal fin as well as on the dorsal and ventral portions of the caudal fin base, this distinguishes the loach minnow from the similar speckled dace for field identification.

Biology

Loach minnow are short-lived fishes, depending on their environment and different characteristics of individual population. Spawning is observed to take place from late winter in early summer. Their eggs are deposited on the bottom of flattened rocks, and the number of eggs can range from 5 to more than 250 per rock, with average of 52-63 eggs per rock. A female can contain have from 150 – 1200 mature ova. Males turn red on their fins an above their mouths when they are ready to breed.

Habitat and Food

Loach minnow can be found at turbulent, rocky riffles of mainstream rivers. They prefer moderate to swift current velocity and gravel substrates. This species are opportunistic benthic insectivores, they seek food at the bottom substrate for riffle-dwelling larval ephemeropterans, simuliid, and chironomid dipterans.

Conservation

Loach minnow was proposed (USDI, Fish and Wildlife Service SFWS1985) and subsequently listed (USFWS 1986) as a threatened species. Critical habitat was proposed (USFWS 1985) and signed into effect on March 8, 1994. It is commonly viewed as endangered by those who work with the fish, and many believe that an endangered listing would be warranted.

References

{{Taxonbar, from=Q3757073 Rhinichthys Freshwater fish of Mexico Freshwater fish of the United States Fish of the Western United States Extinct animals of Mexico Fauna of the Sonoran Desert Endemic fauna of Arizona Endemic fauna of New Mexico Natural history of Sonora Gila River Endangered fish Taxa named by Charles Frédéric Girard Fish described in 1856 ESA endangered species Species endangered by habitat fragmentation Species endangered by damming Species endangered by invasive species