The general husbandry and management principles for the cultivation of aquatic animals are similar to those for terrestrial agricultural animals, although there are some unique differences. Appropriate environmental conditions, a good source of stock, appropriate nutrition, and health and biosecurity measures all should be included when evaluating aquatic animals or an aquaculture facility. Environmental conditions depend on the species being maintained and include a contaminant- and disease-free source of water, acceptable water quality parameters (eg, temperature, dissolved oxygen, pH, ammonia, nitrites, nitrates, salinity, etc), and adequate biofiltration. All of these factors must be optimized for best health and productivity of the aquatic animals. The water may be from a ground (well or spring), surface (river, stream, lake, or pond), or municipal water source, each of which has advantages and disadvantages. The water may be used in flow-through, static, or recirculation systems. Flow-through systems (eg, raceways, cages, and net pens) rely on a steady flow of new water to provide optimal water quality and remove toxic nitrogenous waste products. Conversely, recirculation systems use less water but rely on supplemental mechanical and biological filtration devices to remove nitrogenous wastes and return the water to a reusable condition.
The source of fish stock depends on the species being cultured. A number of fish species such as trout, salmon, catfish, tilapia, and koi are almost exclusively derived from domesticated captive broodstock, while other less-domesticated species such as striped bass and their hybrids, perch, flounder, and cobia are obtained from wild-caught broodstock. Other aquatic species, such as tuna, eel, and some molluscs and crustaceans, are still collected from the wild as juveniles and raised in captivity to market size. Interestingly, except for a very few unusual species, most of the freshwater tropical fish are bred from captive broodstock, while most of the marine tropical fish species are still wild caught. Obviously, the more domesticated the stock, the greater the opportunity for manipulation of the life cycle, disease control, and genetic improvement.
Nutrition plays an important role in determining the growth, health, and reproductive development of the fish. Feed and feed delivery comprise the largest cost to intensive aquatic animal production. Historically, only 2 scientifically prepared diets were commercially available, one for trout (carnivore diet) and one for catfish (omnivore diet). Consequently, most prepared diets available today are modifications of these diets and designed for the specific needs of the species being maintained. Prepared feeds of various sizes depending on the life stage being fed are commonly distributed to the fish by hand, automatic feeders (eg, demand, belt, and vibrator feeders), or blowers. In addition, many species of fish are not well adapted to prepared feeds, especially during the larval and early juvenile stages, and therefore require live food items (eg, zooplankton, brine shrimp).
Last full review/revision July 2011 by Stephen A. Smith, DVM, PhD