A fish cultivation net 3 has a rhombically netted form made by arranging a large number of waved wires 6 in parallel such that the adjacent wires are entwined with each other at their curved portions 6a. The wires 6 has a composition containing 62 to 91 mass % of Cu, 0.01 to 4 mass % of Sn, and the balance being Zn. The Cu content [Cu] and the Sn content [Sn] in terms of mass % satisfy the relationship 62≦[Cu]−0.5[Sn]≦90. The copper alloy material has a phase structure including an α phase, a γ phase, and a δ phase and the total area ratio of these phases is 95 to 100%.