Abstract
The role of plant nutrients in determining feeding preference of triploid grass carp, Ctenopharyngodon idella Val. was investigated. Feeding preference of grass carp was evaluated in two feeding series for Cabomba caroliniana, Hydrilla verticillata, Myriophyllum spicatum and Myriophyllum brasiliense. Nine fish were used in feeding series I and thirteen fish were used in feeding series II. Eleven nutrients (crude protein, acid detergent fiber, phosphorus, potassium, magnesium, calcium, sodium, manganese, zinc, copper and iron) were determined for all plants. Grass carp showed higher overall preference for H. verticillata than the other plants. Feeding preference was significantly correlated with certain plant nutrients. A multiple regression equation calculated from the combined data for the twenty-two fish showed that preference could be predicted by crude protein, phosphorus, calcium, sodium and iron. Plants were discriminated into high preference and low preference groups by a combination of crude protein, phosphorus, potassium, magnesium, manganese and iron, in a discriminant equation computed from the combined data for the twenty-two fish. The role of nutrients in feeding preference shown in this study may explain some of the inconsistencies in earlier studies of feeding preference. Because the concentration of plant nutrients may be site specific, and preference directly influences consumption rate, it is necessary to investigate the relationship between nutrients and grass carp feeding preference in other areas. Such knowledge would be important to develop models to accurately determine grass carp stocking rates.
Woli, Urbe Yoele (1994). Grass carp feeding preference in relation to plant nutrient content. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1554988.