Abstract: A trap capable of harvesting commercial quantities of shrimp in the open ocean or in ponds is a wire mesh cage having shrimp capture gates in the form of truncated prisms, each sized to admit desired shrimp but exclude predatory fish. The inner end of each gate has a transparent hinged flap which swings away to admit a shrimp; to encourage the shrimp's entrance, a gap, sufficient to pass the shrimp's feelers, is left below the flap in the gate. An attractor is provided in the harvester to attract plankton or similar shrimp food organisms. The resulting higher density of plankton at the harvester rapidly attracts shrimp. The mesh construction of the cage permits free flow of water currents, and rapid build up of plankton. The mesh is also opened at least at the bottom of the harvester, to provide size selection, by permitting the ready escape of immature shrimp of small size.