Temporal Variation in Microhabitat Use and Spatial Relations in the Benthic Fish Community of a Stream

Abstract

-Patterns of microhabitat use and overlap among five benthic fish species in a fifth-order stream were investigated during two same-year sampling periods characterized by high vs. low discharges. Microhabitat use patterns for Cottus carolinae (banded sculpin), Etheostoma bellum (orangefin darter), E. blennioides (greenside darter), E. maculatum (spotted darter) and E. zonale (banded darter) were similar to literature reports. During high flow, most segregation occurred along a depth/substrate roughness gradient while in low flows segregation was more common along a velocity gradient. Less segregation in microhabitat use during low flow was probably due to differences in spatial overlap. Five species pairs exhibited high spatial overlap (>0.60) during high flow, whereas one pair exhibited this pattern during low flow. Overall, there was a decrease in spatial breadth (13.91 vs. 10.57) and overlap (0.52 vs. 0.36) of microhabitat use during the low flow period.