Species specific behavior is an important consideration when selecting a shrimp species for culture, as well as selecting a harvest method. Some species such as P. vannamei and P. merguiensis are relatively easy to harvest by draining the pond. These species normally run with the drain water and do not "hang-up" in the pond by burrowing into the bottom, or by stranding. Other species, such as P. japonicus, P. indicus and P. monodon do not always run readily with the drain water and may either strand or burrow into the bottom. With these species, night drains, partial harvests with various nets, and rapid water draw-down to create faster currents may be needed to guard against crop loss, or lost quality due to picking dead shrimp off or out of the pond bottom. The use of canals within the ponds can also aid harvest with these species since they create faster water currents at the termination of the drain harvest, as well as a much reduced bottom area where the shrimp are likely to remain (Fast, 1992).