Growth performance of G2 juvenile blue swimmer crab, Portunus pelagicus (Linnaeus1758), reared in different culture conditions

The experiment was aimed to describe the growth performance of the second generation (G2) of domesticated blue swimmer crab, Portunus pelagicus. The crablet stage was cultivated in three different outdoor rearing conditions: a) each crablet was placed individually in 250 ml-plastic (plastic-cup), b) crablets were reared in an 8 m2 concrete tank with shelters (concrete), and c) crablet reared in the 90-t concrete tank with sandy bottom (sandy-bottom). The crab was fed a commercial prawn diet, and the growth and survival rate (SR) were recorded. The result showed that the final weight (W) and carapace width (CW) in all treatments were significantly different (P>0.05), where the highest in sandy-bottom followed by concrete and plastic-cup. However, there was no significant difference (P>0.05) in the W and CW between the female and male crabs from concrete and plastic-cup systems. Still, males grew significantly higher than females (P<0.05) in sandy-bottom. Meanwhile, the SR varied between rearing conditions. The highest SR was recorded in plastic-cup (97%), in contrast to 52% and 32% for concrete and sandy-bottom, respectively. In addition, a part of the female crab from the sandy-bottom population could have reached the mature stage at the end of the experiment.