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shallow water and moderate current. <br />Usually found in clean, clear waters, pop- <br />ulations are found in some areas of high <br />organic enrichment. <br />Longnose dace are omnivorous, taking - <br />what is available dependent on season <br />and flow (Gerald 1966). Various aquatic <br />invertebrates comprise the main portion <br />of the diet. Longnose dace evidently have <br />an extended spawning period since males <br />in breeding colors have been collected <br />from April to August in Colorado. In the <br />Rio Grande the longnose dace has been <br />found to hybridize with the Rio Grande <br />Chub (Suttkus and Cashner 1981). <br />Though the longnose dace is abundant <br />in portions of Colorado, fishermen do not <br />normally use the species as a bait fish. <br />SPECKLED DACE <br />Rhinichthys osculus (Girard) <br />A streamlined, torpedo-shaped min- <br />now; mouth inferior, overhung by snout; <br />frenum absent, small barbel at each cor- <br />ner of mouth; dorsal fin with 8-9 rays; <br />lateral line complete and straight; <br />peritoneum dark brown, or at least with <br />dark patches. The speckled dace is much <br />like the longnose dace (see previous <br />account). <br />Coloration of adults varies. Speckled <br />dace are tan to gray on the back, fading <br />to white on the stomach with dark <br />speckles often present on back and sides. <br />Breeding-colored males have red-orange <br />on the corners of the mouth, cheeks, and <br />fins. Large individuals may be gray-black <br />on their backs, fading to white on the <br />stomach with a distinct dark band on <br />sides extending from head to tail. <br />Speckled dace may attain a length of 4.5 <br />inches. <br />Range: Speckled dace are found in the <br />western United States from Washington <br />south to Colorado. In Colorado, the spe- <br />cies is restricted to West Slope rivers and <br />streams. The species is abundant in <br />medium to small-sized trout streams. <br />Habitat: Like the longnose dace, the <br />speckled dace is found in riffle areas with <br />gravel substrates. The speckled dace can <br />tolerate rather high nutrient enrichment <br />attributable to effluents from sewage <br />treatment plants. This dace is omniverous <br />and spawns in the spring and summer and <br />is not widely used as a bait fish, despite <br />its abundance. <br />The speckled dace and the longnose <br />dace are alike. In 1891, Jordan noted that <br />about half the speckled dace collected in <br />western Colorado had a distinct frenum, <br />which would make these specimens <br />Family Cyprinidae Genus Rhinichthys <br />Speckled dace. <br />i <br />• ? i ?? 0 I <br />I <br />L <br /> <br />v 17 <br />I <br />-J ' - <br />Distribution by County of the speckled dace. <br />r --` <br />I I <br />-- - - T <br />I <br />1-J <br />i j <br />-1 F_ <br />I <br />I <br />I ?a <br />I <br />I <br />3 I _, ?I <br />i <br />r? <br />I <br />i <br />Colorado's Little Fish 24 <br />Adult male longnose dace in breeding colors.