Food Of The Black Bullhead (Ictalurus Melas) In A New Reservoir

Stomach contents of black bullheads (Ictalurus melas) collected from inshore areas of newly impounded Beaver Reservoir by electroshocker revealed distinct differences in diet between periods of relatively stable water levels and rapidly rising water level. During stable water level periods, Entomostraca formed 72 percent of the volume of food of young-of-the-year bullheads (<4 inches, total length). Filamentous algae, organic detritus and crayfish made up 94 percent of the food volume found in 4.0-11.3-inch bullheads collected during these periods. Contrastingly, during winter-spring months when water level rose and inundated basin soils for the first time, bullheads over four inches ate predominantly terrestrial animals (56% by volume). Earthworms comprised 28 percent of the total volume, followed by a wide representation of insects (15 percent), particularly grubs and caterpillars. Slugs, spiders, centipedes, millipedes, pill bugs and a worm snake were recorded. Filamentous algae remained an appreciable (26 percent) component of the food consumed. Black bullheads (four to eight inches in length) were collected in offshore areas at night by midwater trawl during the summer. Stomach contents were comprised almost entirely (98 percent) of the phantom midge, Chaoborus.

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58936