Adaptation strategies of juvenile grass carp (Ctenopharyngodon idella) facing different dissolved oxygen concentrations in a recirculating aquaculture system

• DOI: 10.1016/j.watbs.2023.100202
• Publication Date: 2023-07-14T02:14:28Z
• Authors: Xinglei Wu; Dapeng Li; Jiamin Lu; Lu Liu; Qiushi Yang; Rong Tang; Xi Zhang; Li Li
• Keywords: Grass carp; Respiration rate

Fishes exposed to different dissolved oxygen concentrations over prolonged time periods have susceptibility and adaptation mechanisms. In this study, healthy grass carp with an average weight of 214.6 ± 18.7 g were selected for long-term culture in recirculating aquaculture systems at three concentrations, i.e., 3.00 mg/L [(2.57 0.33) mg/L, DO2.57), 5.00 [(4.61 0.11) DO4.61], which was the control group, 7.00 [(6.50 0.48) DO6.50]. Blood, gill, muscle, liver samples collected after 60 d. Using hematoxylin-eosin (HE), alcian blue periodic acid Schiff (AB-PAS) staining, determination respiratory metabolism enzyme activity, fluorescent quantitative PCR, adaptability juvenile facing levels explored. The results showed that respiration rate increased, hemoconcentration hemoglobin (Hb), electrolyte pH changed DO2.57. Furthermore, gill lamellae became thinner longer, distance between them mucus on decreased interstitial cell mass decreased. addition, relative expression apoptosis-related genes bcl-2 bcl-xl tissue decreased, while caspase-3 bax increased. muscles tissues, lactate dehydrogenase (LDH) activity lactic content (LA) pyruvate (PDH) related metabolic enzymes PDH-A4 PDH-E1α also accordingly. consumption significantly (P < 0.05). At DO6.50, lamellae, numbers red blood cells (RBC) wheras PDH, PDH-E1a Different affected behavior, structure, transport capacity carp. summary, strategies when systems. © 2021 Authors. Production hosting by Elsevier B.V. This is open access article under CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).