The reintroduction of the Rio Grande silvery minnow (Hybognathus amarus) into the Big Bend region of Texas and Mexico

Authors: Robert J. Edwards, Gary P. Garrett, W. Jason Remshardt, Aimee Roberson

Year: 2012 (xliv)

Abstract

The Rio Grande silvery minnow (Hybognathus amarus) is one of the most endangered fishes in North America and was first federally listed in 1994. Originally inhabiting the Rio Grande from Española, New Mexico to the mouth of the river near Brownsville, the species is currently found in approximately 5% of its former range in central New Mexico. The Recovery Plan for the species recommended that it be reintroduced into portions of its former range. The first experimental reintroductions of the species was approved and undertaken in December 2008. More than 2,000,000 minnows have been released in the Big Bend region in the past 5 years. The reintroduced fish have shown at least some survival at each of the sites and have been found considerable distances away from the reintroduction sites. Rio Grande silvery minnow eggs have been collected from two of the monitoring sites in 2010 and in August 2010, a 37 mm standard length juvenile Rio Grande silvery minnow was taken at one site, indicating some successful reproduction.