Comparison of Hybrid Carp and Grass Carp with Respect to Food Preference, Food Consumption and Growth

摘要

To compare the grass carp and the hybrid carp in their relative effectiveness in controlling vegetation, it is ideal to raise these fishes under controlled laboratory conditions at similar stocking densities. The objective of this investigation is to compare grass carp and hybrid carp relative to vegetation preference, food consumption, and growth rates. Three types of vegetation, pondweed, coontail and milfoil, were provided. Both the fishes showed preference to pondweed with significantly high food consumption rate followed by milfoil and coontail. It was also evident that milfoil was consumed at a greater daily rate than the coontail. Since hybrid carp of the size used in the study had the same food consumption rates and vegetation preferences as that of grass carp, it is safe to say that hybrid carp food habits are similar to grass carp. Since grass carp and hybrid carp lost weight on coontail and milfoil, it is assumed that these weeds did not contribute to growth even when consumed along with pondweed.