Geology topics
Publications and source records attributed to R.W. Rottmann.
Hybrid grass carp fry ( Ctenopharyngodon idella × Aristichthys nobilis ) were stocked into 0·04 ha ponds with and without paddlewheel aeration. Fish in the paddlewheel and non-paddlewheel pond, preyed upon identical organisms, but in different proportions. Fish in the paddlewheel ponds grew at significantly greater rates.
Grass carp, Ctenopharyngodon idella , and hybrid grass carp (grass carp ♀× bighead carp ♀ Aristichthys nobilis ), were fed duckweed ( Lemna sp.), hydrilla ( Hydrilla verticillata ), chara ( Chara sp.), filamentous algae ( Odogonium sp., Spirogyra sp.), and trout chow. Grass carp consumed all plants in greater amounts than hybrids. Grass carp grew best when fed hydrilla and trout chow and showed positive growth on all diets. Hybrids grew equal to grass carp when fed trout chow but did not grow on the vegetation diets. Low consumption rates of aquatic plants may indicate that hybrids are questionable as a plant biocontrol agent.