Multi-omics integration reveals the dynamic impacts of stock enhancement on the intestinal health condition in kaluga sturgeon (Huso dauricus)

On October 6th,2023, one thousand kaluga sturgeon were released to Songhua River (119°52'-132°31' E,11°12'-51°38' N) after 2 h adaptive domestication to eliminate the physiological response caused by transport stress. Before wild reintroduction to river, non-toxic fluorescent dye was injected into the snout of kaluga sturgeon, which was beneficial to catch them again. On the 0 d (Ori), 7 d (D7FL), 14 d(D14FL) and 30 d (D30FL), three kaluga sturgeon individuals were recaptured randomly using seine nets. We performed a series of experiment to assess the dynamic effects of stock enhancement on the gut health conditions. Overall design: On October 6th,2023, one thousand kaluga sturgeon were released to Songhua River (119°52'-132°31' E,11°12'-51°38' N) after 2 h adaptive domestication to eliminate the physiological response caused by transport stress. Before wild reintroduction to river, non-toxic fluorescent dye was injected into the snout of kaluga sturgeon, which was beneficial to catch them again. On the 0 d (Ori), 7 d (D7FL), 14 d(D14FL) and 30 d (D30FL), three kaluga sturgeon individuals were recaptured randomly using seine nets. All subject individuals were anesthetized by the intake of tricaine methane sulfonate (MS-222, BIOZYM, China) after the body weight and length were recorded. Blood sample was collected from caudal vein and stored into sterile blood-collecting vessel with coagulant to separate serum at 4 ?. Finally, intestine tissue samples and gut content were collected into RNase-free centrifuge tubes for the following molecular biology detection and morphology observation. Additionally, residual food debris in stomach also were fixed in anhydrous ethanol to identify feeding habits of kaluga sturgeon during the re-stocking period.