Chitin derived from Daphnia similis and its derivate, chitosan, promote growth performance of Penaeus vannamei

Abstract

Chitin isolated from Daphnia similis and its derivate, chitosan, were prepared to evaluate the effects on the improvement of growth performance of white shrimp, Penaeus vannamei. The diets containing 0.4% chitin or 0.4% chitosan were fed to shrimp for 56 days to evaluate the growth performance of shrimp. A diet without chitin or chitosan supplementation was used as the control diet (herein known as CD). No significant difference in survival of shrimp among groups was observed. The Shrimp fed a diet containing 0.4% chitosan significantly had much higher final weight, specific growth rate and percent weight gain as well as increased its protease activity in hepatopancreas. The feed conversion ratio was also increased in the 0.4% chitosan-fed shrimp. In addition, higher gene expressions of the chitinase (CHT) 3 and chitin synthase (CHS) in hepatopancreas, and the CHT6 and CHS in cuticle were also recorded in chitosan-treated shrimp as compared to CD-treated shrimp. Chitosan derived from chitin of D. similis is considered to have great potential to promote the shrimp growth, by increasing the digestive enzyme and the gene expressions of CHTs and CHSs.