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lip and scales often minute or absent on keel. Adults are dark on top and light below and fins <br />rarely have yellow- orange pigment near base. Adults are usually range from 12 -16 inches long <br />and weigh 3 /4 to 2 pounds. The humpback chub historically ranged in the mainstream Colorado <br />River preferring slower eddies and pools downstream to below the Hoover Dam site, however, <br />present populations are restricted to areas in, and upstream, of the Grand Canyon. <br />Colorado pikeminnow <br />The Colorado pikeminnow (Ptychocheilus lucius), is a torpedo- shaped fish with an olive -green <br />and gold back, silver sides and white belly. The Colorado pikeminnow is endemic to the <br />Colorado River basin, where it was once widespread and abundant in warm -water rivers and <br />tributaries. Wild populations of Colorado pikeminnow are found only in the upper basin of the <br />Colorado River (above Lake Powell). Three wild populations of Colorado pikeminnow are found <br />in about 1,090 miles of riverine habitat in the Green River, upper Colorado River, and San Juan <br />River subbasins. The Colorado pikeminnow thrives in swift flowing muddy rivers with quiet, <br />warm backwaters and are primarily piscivorous, but smaller individuals also eat insects and other <br />invertebrates. These fish spawn between late June and early September and when they are 5 to 6 <br />years old and at least 16 inches long. Spawning occurs over riffle areas with gravel or cobble <br />substrate. The eggs are randomly splayed onto the bottom, and usually hatch in less than one <br />week. <br />Bonytail chub <br />The bonytail chub (Gila elegans), is a highly streamlined fish, dark on top, light below, often <br />very dark in clear waters and pale in turbid waters. Fins are dusky with yellow pigment near <br />base, preferring eddies and pools, not swift currents. The bonytail chub has a concave skull <br />arching into a nuchal hump predorsally with a long and slender snout that does not overhang the <br />upper lip. Scales often minute or absent from chest, stomach. Adults of seven years of age can <br />be 14 inches long and weigh more than one pound. Found historically throughout the Colorado <br />River Drainage however, in recent years bonytail have only been taken from the Green River in <br />Utah and lakes Havasu and Mohave. <br />Razorback sucker <br />The razorback sucker (Xyrauchen texanus), is brownish -green with a yellow to white- colored <br />belly and has an abrupt, bony hump on its back shaped like an upside -down boat keel. Razorback <br />suckers are found in deep, clear to turbid waters of large rivers and some reservoirs over mud, <br />sand or gravel and like most suckers feeds on both plant and animal matter. Razorback suckers <br />can spawn as early as age 3 or 4, when they are 14 or more inches long. Breeding males turn <br />black up to the lateral line, with brilliant orange extending across the belly. Depending on water <br />temperature, spawning can take place as early as November or as late as June. In the upper <br />Colorado River basin, razorbacks typically spawn between mid -April and mid -June. <br />Mexican spotted owl <br />The Mexican spotted owl (Strix occidentalis lucida), is medium sized with dark eyes and no ear <br />tufts, brownish in color and heavily spotted with white or beige. Spotted owls are residents of <br />Page 6 <br />