Fish Assemblage Structure in Relation to Environmental Variation among Brazos River Oxbow Lakes

摘要: Abstract Fish assemblages and habitat conditions of oxbow lakes the main channel middle-lower Brazos River, a meandering lowland river in east central Texas, were investigated during summer 1994. All oxbows eutrophic, with chlorophyll-a levels up to 640 μg/L. Assemblage structure showed large between-lake variation that was explained by both physical biotic variables, combinations water depth, dissolved oxygen, nutrients, turbidity, plankton densities accounting for 45–59% abundance dominant species. Water depth nutrient concentrations best predictors species diversity fish abundance. Periodic desiccation shallow, vegetated created harsh favored small fishes are efficient colonizers. The two youngest relatively deep contained high biomass fishes. Of 42 collected, several largely restricted lakes, others we...