The design of the cage may be circular or square, and sophistication ranges from homemade floating bamboo cages to commercially produced cages with high quality materials. Broodstock are often held in land-based tanks alongside nursery operations. Once the nursery stage is complete, fingerlings are transferred to the net cages where they are grown to market size. Feeding is conducted daily, and size grading occurs once a month to reduce the risk of cannibalism. Net cages should be moved every 2-3 years to prevent negative impacts to the bottom habitat below. The floating cages are often homemade with locally available and inexpensive materials. Many marine fish species are commonly raised this way.