Residue depletion of sarafloxacin and its impact on the intestinal microbial community in Yellow River carp (Cyprinus carpio haematopterus) following multiple oral administration

Sarafloxacin was orally administered to healthy Yellow River carp ( Cyprinus carpio haematopterus ) maintained at 24 ± 0.5 ℃, at a dose of 20 mg/kg body weight (BW) once daily for six consecutive days. Plasma and tissue samples—including skin + muscle, liver, kidney, gill, intestine, and bile—were collected at 3, 6, and 12 h, and at 1, 3, 5, 7, 10, 12, and 15 days following the last administration. Sarafloxacin concentrations were quantified using high-performance liquid chromatography (HPLC). T