Aquarium studies on the consumption of small animals by O–group grass carp, Ctenopharyngodon idella (Val.)

In aquarium experiments common invertebrates from streams and ponds were offered to O‐group grass carp, Ctenopharyngodon idella (Val.) in the presence of palatable plants. When there was no cover for the prey to hide under, the carp ate many of the invertebrates, but when stones were provided, considerably more invertebrates escaped. Rainbow trout eggs were not eaten, but trout fry were taken as soon as they had emerged from artificial spawning redds. While searching for food, grass carp never disturbed the stones covering possible food organisms.