Recruitment of Two Non-native River-Spawning Fishes in Lake Texoma, Oklahoma and Texas

Abstract

The impoundment of a river alters environmental conditions to the extent that some important life history requirements of lotic-adapted fishes are disrupted; changes in requisite conditions for reproduction can interfere with spawning and recruitment. Water movement stimulates spawning migration as well as providing buoyancy to maintain eggs in suspension during development. These requirements can be met for reservoir  populations if the fish can access adequate flowing water conditions in tributaries. Two non-native river-spawning fishes, Grass Carp (Ctenopharyngodon idella) and Striped Bass (Morone saxatilis) have become established in Lake Texoma; both have spawned in the Red and Washita Rivers and have been recruiting in the lake environment. Based on relative abundance of each species in the 2017 samples, we consider that both produced a strong year class. Successful reproduction for the exotic Grass Carp might be expected in some of the other 10 inland reservoirs where Striped Bass spawning occurs.