鱼菜共生，又称养耕共生、复合式耕养，指的是结合了水生动物中的粪便和水中的杂质分解过滤，主取氨（尿素）成份供应给饲养箱上的蔬菜，同时蔬菜的根系把饲养箱内的水净化供给水生动物使用，结合水产养殖（Aquaculture）与水耕栽培（Hydroponics）的互利共生生态系统。在一个鱼菜共生系统中，来自一个水产养殖系统的水被输送到水栽系统，其中副产物是由硝化细菌分解成硝酸盐和亚硝酸盐，它们由植物利用作为营养物。水然后再循环回到水产养殖系统。

在饲养箱（池）中，可以养殖吴郭鱼、锦鲤或宝石鲈等鱼种。池子的水带有鱼的排泄物，含有氮、氨等成分，若直接排到河川、土壤，会造成环境的负担；不过，若拿这些废水来种菜，反而提供蔬菜养分，而且蔬菜净化水质后又可以导回鱼池再利用。这一套平衡系统，能避免水质恶化，且形成鱼帮菜、菜帮鱼的良性循环。

Aquaponics /ˈækwəˈpɒnᵻks/, refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by nitrification bacteria into nitrates and nitrites, which are utilized by the plants as nutrients, and the water is then recirculated back to the aquaculture system.