Effect of salinity on the growth performance, osmolarity and metabolism-related gene expression in white shrimp Litopenaeus vannamei

•The shrimps reared at salinity 20 psu and 30 psu were higher in final weight, weight gain, and growth ratio.•The shrimps reared at salinity 2 psu were significantly lower in growth performance and survival.•The Na+-K+-ATPase α-subunit and carbonic anhydrase mRNA levels at salinity 2 psu and 10 psu were increased significantly.•The chymotrypsin and trypsin mRNA level at salinity 10 psu and 2 psu were down-regulated. An 8-week feeding trial was conducted to study the effect of long-term low-salinity stress on the growth performance, and expression of osmolarity and metabolism-related genes (Na+-K+-ATPase α-subunit and in gills, trypsin and chymotypsin in hepatopancreas) in white shrimp (L. vannamei). Four groups of the white shrimp (mean initial weight, 0.31±0.02g) were cultivated at salinity of 2, 10, 20 and 30psu for 8-week. All treatments were conducted in triplicate of 40 each. The results indicated that shrimps reared at salinity 20psu and 30psu were significantly higher in final weight, weight gain and specific growth ratio than the other treatments (p