The purpose of this study was to investigate patterns of size-specific habitat use by banded sculpin (Cottus carolinae) in Brawley's Fork (Cumberland River Basin, TN). In a survey of three riffle and three pool habitats in a first order stream, adults were found almost exclusively in the pools, while young-of-the-year (YOY) were found almost exclusively in the riffles; juveniles were found in both habitat types. In-stream habitat-choice chambers were used to examine the velocity and depth preferences of juveniles and YOY sculpin and to determine the influence of adult presence on habitat selection of juveniles and YOY. Size-specific habitat segregation is not related to velocity differences between pool and riffle habitats. None of the size classes demonstrated a velocity preference, and the presence of adults did not affect the velocity use of the juveniles or YOY. However, adults showed a strong preference for deep habitat, YOY tended to prefer shallow habitat, both when alone and when in the presence of an adult, and juveniles strongly preferred deep habitat when no adult was present, but chose shallow habitat in the presence of an adult. The ontogenetic habitat shift from riffles to pools by juvenile sculpin may be explained by a change in predation risk as sculpin grow. The most significant predation risk to smaller sculpin is posed by larger piscivorous fish, which primarily inhabit deeper pool habitats. The greatest risk of predation for larger sculpin is posed by piscivorous mammals, reptiles, and birds, and this risk is minimized by the fishes' use of deeper pool habitats. The timing of this habitat shift appears to be a function of the density of adult sculpin, which are potential competitors/predators of the juvenile sculpin.
|Original language||English (US)|
|Number of pages||12|
|State||Published - 2005|
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics