Synergistic interactions between fish and stoneflies: facilitation and interference among stream predators

摘要: A series of experiments examined rates prey consumption by mottled sculpins (Cottus bairdi) and perlid stoneflies (Agnetina capitata) separately, when they were together in artificial streams. Two types Ephemeroptera (Ephemerella subvaria Baetis tricaudatus) used separate experiments. When both predators present larvae was significantly less than model predictions combined consumption, indicating a negative interaction between predators. Consumption Ephemerella higher predicted the positive Analysis gut contents indicated that Agnetina captured fewer presence sculpins, more stoneflies. Negative effects on number found even unable to feed. Positive still density reduced half. Understanding complexity fish may provide explanations for contradiction observed expected results removal