Monday, September 13, 2010
Hall B (Convention Center)
Feeding periodicity, diet composition, and diet overlap of common shiner (Luxilus cornutus), cutlips minnow (Exoglossum maxillingua), and fallfish (Semotilus corporalis) was examined in the Salmon River, New York. Fallfish and cutlips minnow had similar patterns of feeding activity which increased throughout the day peaking at 2000h. The feeding activity of common shiner increased during the day, peaking at 1600h, then decreased until 0800h. Chironomids were the major prey taxa consumed by common shiner and cutlips minnow at all periods over the diel cycle whereas ephemeropterans were the major prey of fallfish. Common shiner and cutlips minnow had less variability in diel diet composition than fallfish. Diet overlap among species was high only between common shiner and cutlips minnow (0.89) and lower between common shiner and fallfish (0.54) and cutlips minnow and fallfish (0.50). The diets of common shiner and fallfish were more closely associated with the composition of the drift rather than the benthos whereas the diet of cutlips minnow was slightly more associated with the benthos. These results show differences in prey consumption, diel feeding activity and location of foraging between these three species of cyprinids in the Salmon River.