Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Watershed Sciences

Department name when degree awarded

Fisheries Management


Not specified


A series of ponds in northern Utah supplied mainly by artesian water was poisoned with rotenone during 1949-50. Four hundred and seventy-three fish were obtained for a food habits study, and of these fish, 423, or 89 percent, had food in their stomachs. The species studied were largemouth bass, green sunfish, common bluegill, and black bullhead. Largemouth bass had the widest variety of diet throughout the year but also had the highest percentage of empty stomachs. Green sunfish and black bullhead had the least diverse food habits. Twenty-nine different food items were recorded; those used most commonly were green sunfish, dragonflies of the families Aeshnidae and Libellulinae, the water boatmen Hesporcorixe, midges of the family Tendipedidae, fresh-water shrimp, and certain algae. Largemouth bass fed characteristically on green sunfish and dragonfly naiads. Bass appeared to select foods--insects seemed to have been substituted for fish, and fresh-water shrimp for insects. Dragonflies, water boatmen, and midge larvae occurred in that order in volume and in frequency. Green sunfish fed largely on insects, particularly dragonfly naiads, and fresh-water shrimp. Fish were rarely taken by them. Bluegills had a food habit pattern similar to green sunfish. However, insects used most often by the bluegill were midge larvae and water boatmen. Although the diet of bullheads was omnivorous in nature, the bulk of the volume was made of fish, plants, and shrimp. They ate more molluscans than the centrarchids. Certain food items were consumed by one species alone. Bass only took backswimmers, (Notonecta), water striders, (Gerris), and field mice, (Microtus). Bees, ostracods, and spiders were food for bluegill alone. Bullheads were the only fish that fed on bivalves. Green sunfish had no distinctive dietary habit.