Sonora Sucker (Catostomus insignis) is a medium-sized (over 0.76 m long) fish that occurs in the upper Gila River and Bill Williams River system in Arizona, the Gila and San Francisco drainages in New Mexico, and the headwaters of the Santa Cruz and San Pedro in Sonora, Mexico. They inhabit a variety of habitats, from warm rivers to trout streams, using shade in rocky pools during the day and deep riffles during the night. They are most active in early morning and late evening.