rate of some organisms since they may become too large to be 

 consumed by the cultured animals, may become predators on the 

 cultured animals, or may compete with them for other natural food 

 organisms . 



Other unprocessed fish foods include organ meats such as liver, 

 kidney, and heart, cut fish, and various forms of organic detritus. 

 The latter, resulting from the culture of other aquatic organisms, 

 is the preferred feed for some fish species, molluscs, and 

 crustaceans. Organ meats and cut fish are fed generally to large 

 finfishes, but are expensive. 



Formulated Feeds 



Formulated feeds are widely used in intensive production systems 

 and are of two general types: complete and supplemental. Complete 

 feed formulations contain all the dietary nutrients needed for 

 growth and reproduction. They are used in raceways, circular 

 pools, silos, and high intensity production earthen ponds where 

 natural foods are not available, or are present in insufficient 

 amounts to meet the needs of the organisms. 



Supplemental feeds are usually fed in low- intensity production 

 systems. They contain the most important growth nutrients in the 

 culture system — usually protein and energy. Natural foods are 

 relied upon to balance the diet. 



Fish feed formulations can be manufactured into meals, flakes, and 

 sinking or floating pellets, or moist pellets. The type of 

 formulation fed depends on the size and the feeding behavior of the 

 aquatic animal being cultured. The efficiency of conversion of 

 feed protein into fish flesh depends on how closely the feed 

 formulation meets the nutritional requirement of the species being 

 cultured, the quality of the ingredients, their resistance to 

 leaching or disintegration in water, storage characteristics, and feeding 

 practices . 



Considerable information exists on the nutritional requirements of 

 only a few aquatic animals. Research is needed on the individual 

 requirements of most aquatic animals in order to determine the 

 standard for a "healthy" animal and to increase profitability. 



Effluent Contr ol and Water Availability 



Ponds 



Ponds are normally built on level land by constructing earthen 

 dikes from the excavated bottom, area. They are usually filled by 

 pumping water from wells or irrigation canals. Ponds in hilly 

 areas are formed by constructing earthen dams to contain water in 

 natural basins and are often filled by springs or rainfall run-off. 



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