Comparison of macroinvertebrate assemblages in a first- and second-order stream in Wilber Wright State Fish and Wildlife Area, Henry County, Indiana in 2000

Macroinvertebrate assemblages were semi-quantitatively sampled from the Little Blue River and an isolated headwater stream in Wilbur Wright Fish and Wildlife Area from March through November of 2000. Physicochemical conditions and qualitative habitat characteristics were recorded at each site. Each stream contained unique community assemblages based on taxa richness, composition, functional feeding groups, behavioral groups, reproductive habits, and drought tolerance/avoidance. Collections from the first-order stream contained fewer taxa and a greater proportion of non-insects and tolerant taxa than those from the Little Blue River. Taxa from the Little Blue River were adapted for filtering/collecting and for swimming or clinging, while taxa from the first-order stream were primarily gathering/collecting and swimming or sprawling. The proportion of taxa with adaptations for drought resistance or avoidance was significantly higher in the first-order stream than in the Little Blue River (p