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The loach minnow (Rhinichthys cobitis) is a species of freshwater fish. It is a member of the carp family (family Cyprinidae) of order Cypriniformes. It occurs in streams and small rivers throughout the Gila River and San Pedro River systems in Arizona, New Mexico, and Sonora;[2] it is now considered extinct in Mexico.[1]

Loach minnow
Loach Minnow.jpg
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Subfamily: Leuciscinae
Genus: Rhinichthys
R. cobitis
Binomial name
Rhinichthys cobitis
(Girard, 1856)[2][3]

Tiaroga cobitis Girard, 1856


Loach minnow has an elongated, compressed body with its size rarely exceeding 65 mm (2.6 in) in length.[4] 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.[4] In order to distinguished loach minnow from the similar speckled dace, the loach minnow have 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.


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.[5] A female can contain have from 150 – 1200 mature ova.

Habitat and FoodEdit

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.


Loach minnow was proposed (USDI, Fish and Wildlife Service [USFWS] 1985) and subsequently listed (USFWS 1986) as a threatened species. Critical habitat was proposed (USFWS 1985) and signed into effect on March 8, 1994.


  1. ^ a b NatureServe (2013). "Rhinichthys cobitis". The IUCN Red List of Threatened Species. IUCN. 2013: e.T39285A19033034. doi:10.2305/IUCN.UK.2013-1.RLTS.T39285A19033034.en. Retrieved 10 January 2018.
  2. ^ a b Froese, Rainer and Pauly, Daniel, eds. (2014). "Rhinichthys cobitis" in FishBase. August 2014 version.
  3. ^ "Rhinichthys cobitis". Integrated Taxonomic Information System. Retrieved 12 January 2015.
  4. ^ a b Minckley, W.L. 1973. Fishes of Arizona. Arizona Game and Fish Department, Phoenix. pp. 133-135.
  5. ^ Marsh, P.C. 1991. Loach Minnow, Tiaroga cobitis Recovery Plan; for Region 2, U.S. Fish and Wildlife Service, Albuquerque, New Mexico. Arizona State University, Tempe, Arizona. pp. i-38.