一、前言水产养殖业,又称栽培渔业,近十年来得到了迅速的发展。其原因是世界范围内鱼的需求量不断增加,特别是发达国家,由于海洋捕捞成本的提高、产量不稳定,使供应量减少。而鱼类食品不断开发新产品,也增加了鱼的需要量。水产养殖的产量和品种质量都比海洋捕捞稳定,因此,当前是向水产养殖业投资的良好时机。美国的美洲鲶(Ictalurus punctatus)养殖是个明证,60年代其产量微不足道,到1985年,产量 I. Introduction Aquaculture, also known as cultivation and fisheries, has enjoyed rapid development in the past decade. The reason for this is the increasing worldwide demand for fish, especially in the developed countries, which is destocked due to increased costs of marine fishing and reduced supply. The continuous development of fish food products, but also increased the demand for fish. Aquaculture production and the quality of varieties are more stable than those of marine fishing and, as a result, is a good time to invest in aquaculture. Breeding of the American catfish (Ictalurus punctatus) is a testament to the negligible output in the 1960s. By 1985, production