Effects of four factors on Penaeus monodon post-larvae cannibalism

In order to study the cannibalism behavior of Penaeus monodon post-larvae, the effects of four internal and external factors, such as individual size, post-larvae density (50, 80, 110, 140, 170 ind/L), food abundance and aeration, on the cannibalism rate were analyzed. The results showed that the cannibalism rate was significantly affected by individual size, post-larvae density and food abundance. When post-larval density increased from 50 ind / L to 110 ind / L，the average daily cannibalism rate increased by 358.07%. When larval density was more than 110 ind/L，cannibalism rate slightly increased. The average daily cannibalism rate decreased by 69.81% in 20 ind/mL food group than that of no-food group. The mix of individuals in different sizes could increase cannibalism rate significantly. Sufficient aeration could decrease cannibalism rate. The results indicated that insufficient food was a main reason to cause cannibalism in Penaeus monodon post-larvae. High stocking density and differences of individual size could induce and stimulate the cannibalism．