Design Construction of Collapsible Trap to Catch Mud Crab (Scylla serrata).

Abstract

Collapsible trap is the most popular fishing gear to catch of mud crab. This fishing gear has weakness, because its construction was adopted from other country without any aclimatization with behavior of Indonesian mud crab. The main objective of this research is to determine suitable design of collapsible trap to catch the mud crab. This research consists of two steps. First step is called as research of trap parts. The objectives of this step are to determine suitable mesh size of trap entrance, suitable slope of trap entrance, shape and size of trap entrance, and suitable colour of shelter. Second step is called as new design trap trial. The objectives of this step are to obtain the most productive design of trap and to determine influence of lid instalation at the top of trap as a shelter. The method of all researchs are laboratory experiment. The result showed that the suitable mesh size of trap entrance was 1 inchi, the suitable slope of trap entrance was 40o, the suitable shape of trap entrance was square with height of 5 cm. The distance between wires was 2-3 cm. The colour that was choosen by mud crab was black. So, this colour could be used by the trap as a shelter. The catch number of four types trap were significantly different (Fcount= 95.52 > Ftab= 2.74). Most of mud crabs were caught in new design trap (B) (59.2% from total catch) and fewer crabs were caught by fishermen trap (N) (0,05% from total catch). This trap has dimension of 50 × 50 × 16 (cm). The catch number of trap with lid and without lid was significantly different (Fcount= 125.59 > Ftab= 4.41). The catch number of trap with lid was 89 crabs (96.7% from total catch). While, the catch number of trap without lid was 3 crabs (3,3% from total catch).