A diet of fructose-enriched Artemia improves the response of juvenile Litopenaeus vannamei shrimp to acute low-salinity challenge

The Pacific white shrimp (Litopenaeus vannamei), as an economically important species, has been reared in low-salinity water during the last decade. To investigate how juvenile L. vannamei shrimp fed with fructose-enriched Artemia respond to acute low-salinity stress, the shrimp were randomly divided into four treatment groups, three groups were fed with Artemia enriched with either 100, 200 and 300mgL(-1) of fructose and a control group fed with Artemia with no enrichment for 10days. The results showed that the 300mgL(-1) fructose group demonstrated the maximum survival rate and glycogen content. Additionally, the 300mgL(-1) fructose group showed significantly higher Na+/K+-ATPase activity, total antioxidant capacity, and expression levels of Na+/K+-ATPase -subunit, V-H ATPase -subunit, hexokinase, phosphofructokinase, antioxidants (SOD, CAT, GPX) and Hsp70 mRNA when compared with the control group. Furthermore, after exposure to low salinity, the mRNA levels of phosphofructokinase, V-H ATPase -subunit, GPX, p38, JNK and Rac1 stayed constant in shrimp fed with fructose-enriched Artemia but changed significantly in the control group. Thus, a diet of fructose-enriched Artemia can improve the osmoregulation and survival of juvenile L. vannamei shrimp exposed to low salinities.