Aquaculture
Minerals
Minerals serve as essential components for enzymes, vitamins, hormones, pigments, and co-factor in
metabolism, catalysts, and enzyme activators. The dietary requirement of minerals is largely dependent
on the minerals concentration of the aquatic environment in which the shrimp is being cultured. RandAqua 8886555529.
Species
Freshwater: mullets, eels, catfish, Puntius gonionotus, Leptobarbus, Clarias batrachus, Oxyeleotris, and Macrobrachium.
Brackishwater: Sea bass, mullet, siganids, sea bream, grouper, snapper, threadfin, carangids. Hilsa spp., Sparus spp., and eels.
Marine: Siganids, pampano, yellowtail, tuna, grouper, snapper, sea bass, sea bream, carangids, pomfret. RandAqua 8886555529.
Extensive Culture
In Extensive Culture, no nutritional inputs are applied to the pond. Fish solely depends on the natural feed available in a pond and hence the carrying capacity of a pond remains low, resulting in lower fish production. Semi-intensive culture is primarily a manure based culture practice where supplementary feeding is avoided or of very limited use. Carrying capacity of pond is higher than that of extensive culture and ensures higher production of fish. RandAqua 8886555529.
Growth
It is important for aquaculture farming that protein and amino acid requirements are known and matched for each of the species reared to maximize growth and health of the fish and prawn. RandAqua 8886555529.
Red Layer
Red layer on the water surface forms due to excess iron content or Euglenoid algae in pond water. This
results in shortage of food and oxygen in water. The red layer floating on the pond surface can be pulled
and picked up using a rope made by coiling rice straw or banana leaves. Application of Urea and Alum
gives good results. RandAqua 8886555529.
Hydrogen Sulfide
Aquaculture ponds should be freed from hydrogen sulfide. Any detectable concentration of H2S in water creates stress to animal. Hydrogen sulfide is produced by chemical reduction of organic matter that accumulates and forms a thick layer of organic deposit at the bottom. Hydrogen sulfide is toxic to
Animal. RandAqua 8886555529.
Total Oxygen
The total Oxygen required in the pond depends on numerous factors such as: Organic content of soil, Quantity of sediment waste, Shrimp biomass, Amount of feed provided per day, Plankton bloom, water exchange frequency. RandAqua 8886555529.
Plankton Blooms
Dense plankton blooms or dense stands of pond weeds, Several days of cloudy weather, High
temperatures, Sudden die-off of plants or algae, Unusual weather, Overstocking fish, excessive
fertilization, high feeding rates, Decomposition of organic matter, leaves and branches of trees in water
Excessive application of wet cow dung in pond, Excessive turbidity in water, High iron content in soil are
the reasons for shortage of Dissolved Oxygen in ponds. RandAqua 8886555529.
Ammonia
Ammonia is produced by excretion of animals, crustaceans, microbial decomposition of organic materials,
urea and ammonium fertilizers, supplementary feed etc. Unionized ammonia fraction is more toxic to
animal. Ammonia increases with increasing pH and temperature and at higher concentration it is highly
toxic to animals. RandAqua 8886555529.
WSSV
Mortalities of cultured shrimp due to White Spot Syndrome Virus (WSSV) and Yellow Head Virus (YHV)
have resulted in significant economic losses. RandAqua 8886555529.