Cage culture is a system in which fish are grown in a cage made of bamboo, metal or wood that is covered with nets. The netting encloses the cage on all sides or on every side except the top, which is left open. There are three types of cages: submersible, floating and fixed. When selecting material for cage construction, there are several criteria to consider, including availability, durability, strength, weight,weather resistance (rot, corrosion), toxicity and, of course, cost. The materials should be smooth and non-abrasive, especially the cage bags.