The Guadalupe bass (Micropterus treculii) is a rare species of fish endemic to the U.S. state of Texas, where it also is the official state fish. It is restricted to creeks and rivers (including the Guadalupe River, hence the name Guadalupe bass), and was formerly listed as vulnerable, but IUCN currently considers the data insufficient to determine its status. Today, most fly fishermen and anglers practice catch-and-release techniques to improve fish populations. The Guadalupe bass is often difficult to distinguish from the smallmouth bass or spotted bass, and the fish is known to hybridize.