R. Wydoski G.A. Mueller 2004 <p>A single stocking of 611 wild flannelmouth suckers <i>Catostomus latipinnis</i> in 1976 represented the first successful reintroduction of a native fish in the lower Colorado River. Flannelmouth suckers ranging in age from young of the year to 24 years were captured during 1999–2001; their population was estimated as at least 2,286 (95% confidence interval, 1,847–2,998). Recruitment appeared sporadic, consisting of consecutive years of low recruitment (&lt;10%) supplemented by a stronger (31%) year-class. Historically, this native fish was rare and was believed extirpated from the lower river by 1975, but it now reproduces naturally in a reach dramatically altered by water development. This successful reintroduction indicates that one native fish can successfully tolerate environmental alterations whereas another, the razorback sucker <i>Xyrauchen texanus</i>, apparently cannot. Other opportunities may exist in altered rivers to benefit native fishes where they were absent or historically rare.</p> application/pdf 10.1577/M02-170 en Taylor & Francis Reintroduction of the flannelmouth sucker in the lower Colorado River article