Effects of Size Grading on Growth and Non-Specific Immunity Factors of the Shrimp Litopenaeus vannamei Boone

摘要

The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [GS, with an average body length (BL) of (3.04 ± 0.36) cm and body weight (BW) (0.412 ± 0.35) g], the large group [GL, with a BL of (4.29 ± 0.55) cm and BW of (1.098 ± 0.42) g], and the ungraded group [Gm, with a BL of (3.47 ± 0.81) cm and BW of (0.611 ± 0.79) g], were reared under the same conditions for 8 wk. Growth performance and non- specific immunity factors were measured. The results showed that BW gain, biomass gain and the specific growth rate of body length (SGRL) were significantly influenced by size grading (one-way ANOVA, P 0.05) was found on phenoloxidase (PO) activity among the three size groups. Synthetically, size grading could enhance growth and rearing efficiency, and did not have a significant influence on the immunity of L. vannamei Boone. Therefore, graded farming in L. vannamei Boone was feasible in the culture practice.