Fishing trials using banana and fish baits in pots for catching marine crabs: an attempt to tropical selective crustacean trapping

Abstract

Experimental fishing targeting marine crabs was conducted using crab pots baited with overripe banana locally known as “latundan”, which is a hybrid of Musa acuminata (Colla 1820) and Musa balbisiana (Colla 1820), and cardinal fish Apogon lineatus (Temminck and Schlegel 1842). This was done to assess the catch composition and to investigate the effect of the baits on the selective catching of the desired crab species, size, and sex during trapping operations. Four bait treatments were used: no bait (NB), banana (BB), fish bait (FB), and banana-fish combination (FB+). Results showed that the FB+ caught comparable P. pelagicus with FB in terms of numbers, and the catch of T. sima was about the same. Pots having NB or BB alone caught the fewest crabs during the trapping operations. The combination of banana and fish baits showed no significant difference in the number of crabs caught when using fish baits. Portunus pelagicus (Linnaeus 1758) and Thalamita sima (Milne Edwards 1834) dominated the catches among crabs comprising a total of 44.21% and 18.95%, respectively. In terms of crab size (carapace width), catches in pots baited with FB alone had smaller crabs in comparison to the catches in pots with FB+, but in P. pelagicus no statistical difference was detected. Moreover, FB+ showed gender neutrality for P. pelagicus, but more T. sima females than males were caught. This shows that banana combined with fish baits has intraspecific selective properties towards some crab species. Furthermore, the addition of bananas to fish baits seemed to decrease the number of non-target species caught. The overall high percentage of crabs caught in the pots baited with FB+ and FB means that these baits may have extra-specific potential in crab trapping thus reducing undesired species trapped in the pots. Furthermore, the inclusion of banana to fish as bait can be beneficial for future studies in resource management and the reduction of fish utilization as bait.