Work

Available phosphorus requirement of juvenile Asian red-tailed catfish (Hemibagrus wyckioides)

Year: 2025

Type: article

Abstract: This study explored the optimal dietary available phosphorus (P) requirement for juvenile Asian red-tailed catfish ( Hemibagrus wyckioides ). Five isonitrogenous (42.00 %) and isolipidic (9.00 %) diets with monocalcium phosphate supplementation levels of 0.00 %, 0.75 %, 1.50 %, 2.25 %, and 3.00 % (namely P0, P0.75, P1.5, P2.25, and P3) were fed to fish for 56 d. Weight gain rate increased with phosphorus supplementation up to 2.25 % and then declined. The apparent digestibility coefficients (ADC) of phosphorus and calcium, as well as the phosphorus and calcium contents in the whole body and vertebrae , exhibited a positive correlation with dietary phosphorus levels, while the expression of intestinal genes related to phosphorus transport and metabolism showed a negative correlation with increasing dietary phosphorus levels. Using quadratic regression, the optimal phosphorus requirement was estimated at 0.87 % based on weight gain and 0.99 % based on vertebrae phosphorus content. Whole body crude lipid content and serum total cholesterol was significantly lower in P1.5, P2.25, and P3 compared to the P0 and P0.75 group ( P < 0.05 ). Liver lipid droplet volume and number were markedly reduced in P2.25 compared to the P0 group. Phosphorus deficiency resulted in stunted growth, reduced bone mineralization , and increased lipid accumulation in whole-body tissue and the liver. These findings provide practical guidance for phosphorus supplementation in H . wyckioides aquaculture, optimizing growth and bone mineralization while minimizing excess phosphorus in feeds.

Source: Aquaculture Reports

DOI: 10.1016/j.aqrep.2025.102818