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<br />historically from the San Juan arm of Lake Powell in Utah, but <br />there are no records, either historic or recent, of this species <br />from the New Mexico portion of the San Juan River. While no <br />individuals were seen or collected during the course of this <br />survey, their absence from our collections does not preclude the <br />possibility of their occurrence in New Mexico. Documentation of <br />the razorback suckers may require a more extensive early spring <br />inventory. <br />Gila complex <br />The Gila complex, as defined here, consists of a suite of <br />three species which includes the roundtail chub, humpback Chub - <br />and bonytail. Historically, roundtail chub was known from the <br />San Juan River and its major tributaries; Los Pinos, Animas, La <br />Plata and Mancos rivers. The earliest New Mexico record is seven <br />specimens collected at Aztec in 1934. Roundtail chub was <br />probably moderately common until construction and closure of <br />Navajo Reservoir in the early 1960's. From 1962 to present, we <br />can only document the collection of 39 individuals at eight <br />stations. The last known collection of a roundtail chub prior to <br />this study was in 1977 in the San Juan River between Fruitland <br />and the Hogback. <br />During October 1987, we collected YOY roundtail chub at <br />three stations (River Miles 193, 170, 160) in seine samples. <br />These backwaters varied in depth from 0.5-1.5 m and substrate was <br />silt-laden cobble. A single roundtail chub (UNM 4821, 163 mm <br />38