PATTERNS OF MICROHABITAT USE AMONG 4 SPECIES OF DARTERS IN 3 APPALACHIAN STREAMS

We used snorkeling techniques to examine patterns of microhabitat use among four species of darters-Etheostoma flabellare, E. blennioides, P ercina gymnocephala and the potentially threatened E. osburni-in three West Virginia streams. Sympatric darter species were generally segreg ated in each stream, based on microhabitat use variables of mean depth , current velocity and substrate type. In all three streams-the East F ork of the Greenbrier River, the Cherry River and Laurel Creek-E. osbu rni was observed in fast current velocities and rock substrate in wate r depths ranging from 20 to 30 cm. In the East Fork of the Greenbrier River and Laurel Creek, E. flabellare was common in slower velocities over predominantly cobble substrate. Percina gymnocephala and E. blenn ioides were spatially segregated from E. osburni on the basis of water column depth. Differences in habitat use may be related to morphologi cal differences between species.