Characterization of Feeding Behaviors, Appetite Regulation and Growth Performance of All-Female (cyp17a1+/-;XX Genotype) Common Carp (Cyprinus carpio).

Genome editing has the potential to improve growth and traits of aquatic animals. Assessment of the feeding habits of the genetically modified farmed fish is necessary, as this is closely related to the assessment of their growth performance, which is one of the most important economic traits. Previously, we developed a novel strategy to produce all-female (AF) common carp (cyp17a1+/-;XX genotype) with genome editing, which exhibited a growth advantage compared to the control carp (including control male and female carp). However, the feeding behavior related to the growth performance of wild-type control and AF common carp remains elusive. The results of feeding and swimming behaviors showed that AF common carp exhibited a faster feeding activities and more active swimming activities, which probably enhanced its growth performance. Brain gene expression analysis revealed AF common carp had a significant upregulation of the orexigenic factors gene expression levels in the fed state, which would further promote the growth of AF carp. Here, AF carp exhibited higher growth performance with higher growth hormone (gh) gene expression. This study provided insight into the growth performance, feeding behaviors and appetite regulation of the genetically modified AF carp and the assessment of feeding behaviors in other genetically modified farmed fish.