Presence of plants like moss is very necessary in pond for successful fish farming. Moss is the primary producing plant of a pond or stream. Plant vorous fish like rui, katla etc. generally survive by consuming moss. Although there are many types of other moss which are food of zooplankton. If there are huge amount of moss in the pond then it increases the fish production. Moss also prevent growth of sinked harmful aquatic plants. Different types of tiny animals, insects, plants grows in the water. Among them plants are known as phytoplankton and animals or insects are called zooplankton. All of this plankton are favorite natural food of fish. This types of plants and animals are helpful aquatic plants and animals for fish farming. A little description about them are described below.
Tiny aquatic plants are called phytoplankton. They are not visible at naked eye. They are of green colored and natural food of fish. For example scenedesmus, navicula, spirogyra, pediastrum, volvox, polytomella, anabaena etc. are phytoplankton. They can produce food for them by photosynthesis. Phytoplankton absorb the carbon dioxide produced by rotation of different types of material in the pond and give up oxygen while producing food. In this process it keeps ecological balance of the pond. Many types of zooplankton also eats this phytoplankton. They are called primary producer of pond because they can produce their own food. They move from one place to another place by tide and wave of water.
Tiny sized animal and insects which are available in the water are called zooplankton. Keratella, brachionus, dafnia, diaptomus etc. are zooplankton. Fish get about 40-70% protein form zooplankton. Zooplankton is favorite food of minnow.