Ctenophora predation by ctenophores may control the populations of small zooplanktonic organisms such as copepods, which might otherwise wipe out the phytoplankton (planktonic plants), which are a vital part of marine food chains. Almost all ctenophores are predators – there are no vegetarians and only one genus that is partly parasitic. If food is plentiful, they can eat 10 times their own weight per day. While "Beroe" preys mainly on other ctenophores, other surface-water species prey on zooplankton (planktonic animals) ranging in size from the microscopic, including mollusc and fish larvae, to small adult crustaceans such as copepods, amphipods, and even
Culture of microalgae in hatcheries Culture of microalgae in hatcheries Microalgae or microscopic algae grow in either marine or freshwater systems. They are primary producers in the oceans that convert water and carbon dioxide to biomass and oxygen in the presence of sunlight. The oldest documented use of microalgae was 2000 years ago, when the Chinese used the cyanobacteria "Nostoc" as a food source during a famine. Another type of microalgae, the cyanobacteria "Arthrospira" (Spirulina), was a common food source among populations in Chad and Aztecs in Mexico as far back as the 16th century. Today cultured microalgae is used as direct feed for humans