The feeding ecology of grass carp: A review

Abstract As an economically important herbivorous fish, the range of grass carp ( Ctenopharyngodon idella ) has expanded in the world and its ecological influences have become more evident. Currently, we have embarked on assessing the effect of grass carp on aquatic organisms and water quality by integrating the outcomes from previous ecological studies. Bibliographical data integration shows that aquatic plant preference is likely to be related to the cellulose proportion, calcium, sucrose and citric acid of the aquatic plant. Moreover, pharyngeal teeth and multiple gene copies of taste receptors could help reveal the feeding mechanism of grass carp. The expansion of the number of sweet‐detecting T1R2 genes, and the functional potential of Umami taste receptor T1R3 by calcium‐regulation was speculated on the basis of previous experimental observations of grass carp, suggesting that aquatic plant consumption by this species is tightly associated with the taste receptors. Apart from the competition in living space between grass carp and other fish, the effects of consuming zooplankton and zoobenthos were summarized to reveal general passive feeding of grass carp, as well as the feeding choice in the absence of aquatic plants. Water quality data were gleaned to make comparative analyses between groups stocking with and without grass carp to uncover changes in water physicochemical parameters in short‐ (<1 year) and long‐term impacts. This review provides insight into the grass carp feeding behaviour and mechanisms and it will help find a balance between ecological harmony and the industrial development of grass carp.