Lotic Environment Affects Morphological Characteristics and Energy Metabolism of Juvenile Grass Carp Ctenopharyngodon idella

This study investigated the effect of a lotic environment on morphological characteristics and energy metabolism in juvenile grass carp Ctenopharyngodon idella. The fish were stocked forced to swim for 12 h per day 4 weeks at three water current velocities 0.5, 2, body length s−1 (Bl s−1). control lentic with 0 Bl s−1. results showed that significantly increased weight, length, condition factor carp. first principal component (PC1) characterized by measured overall size suggested had stoutness wider tail stalk. Standard metabolic rate (SMR), maximum (MMR), aerobic swimming performance (Ucrit) elevated flow positively correlated PC1. group decreased contents serum glucose muscular glycogen, level lactic acid. mRNA expression levels AMP-activated protein kinase-phosphorylate PPAR γ coactivator 1 α-nuclear respiratory (AMPK-PGC1α-NRF1) pathway-related genes upregulated red muscle environment. Water ratios enzymes (lactate dehydrogenase/citrate synthase) cytochrome c oxidase/citrate muscle. relationship between capacity was shaped promote metabolism. identified evidence mechanism trade-off morphology