Description: A small (maximum length of 11 cm [4.3 in.]), fusiform fish with a pointed snout, subterminal mouth, and dark but vague speckling on the sides and dorsal surface. The dorsum is olive-colored with small, diffuse dark spots that may coalesce into a black line on the side, occasionally forming a black spot on the caudal peduncle. The ventral surface is light cream-colored or yellow. There is one dorsal fin, and the tail is deeply forked. During the breeding season, males develop red-orange colors on the fins and around the face (mouth and gill covers). A small maxillary barbel is present at the corner of the mouth.
Diet: Omnivorous. Primarily feeds on the surface of substrate or on food
items drifting within the water column. Diet includes algae, invertebrates,
fish eggs, and detritus.
Habitat: Stream bottoms in shallow cobble riffles. These fish occur in
low-velocity areas behind rocks. Spawning habitat consists of small
patches of bare rocks and pebbles that the males clear of debris.
Range: The species occurs throughout the western United States from
the Columbia River southward to the Colorado River. This subspecies is
endemic to Clark County, Nevada, and is found only in the middle Muddy
River north of Interstate 15.
Comments: Muddy River fishes are more plain, with little or no mottling.