Others were of simpler designs, like squares with a single opening, which funnily seemed to work best. The most complex setup was one where Atchmon tried to build a small dam and 'funnel' the fish into a basket. The only problem was Atchmon couldn't figure out how to make a strong basket for the fish to go in. Until Rarity show him how it's done, though he didn't have the patience for it anymore. Considering he could just spear the fish and be done with it.