Loach minnow


The loach minnow is a species of freshwater fish. It is a member of the carp family 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; it is now considered extinct in Mexico.

Description

Loach minnow has an elongated, compressed body with its size rarely exceeding in length. 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.
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.

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.

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 and subsequently listed as a threatened species. Critical habitat was proposed and signed into effect on March 8, 1994.