Differences in gut morphology of Campostoma oligolepis populations from two watersheds in northwest Georgia, USA

摘要

Populations of stream fishes exposed to different hydrodynamic, trophic, and physicochemical conditions may vary in their phenotypic traits in ways that influence local persistence. For example, gut morphology frequently varies with trophic position and food quality. As a result, one might expect gut morphology to differ between populations from watersheds with unique ecosystem characteristics, such as those occurring in urbanized streams. This study was an initial exploration to determine whether gut morphology of Campostoma oligolepis (Largescale Stoneroller) differed between an urbanized stream and a less urbanized stream in northwest Georgia, USA. Individuals were collected in May and June 2011 and dissected to quantify the gut length and gut quotient. With standard length as a covariate, gut length was shorter in the urbanized stream, and gut quotients were significantly lower. Gut lengths were also significantly longer in May than in June. One possible explanation for this difference is spatial and temporal variation in food sources associated with urbanization, although alternative explanations exist.