AQUACULTURE IN INDIA
NURSERY POND IN SHRIMP CULTURE.
Nursery pond in Shrimp Culture pond:This was one of our suggestion's given to the Shrimp farmers in Andhrapradesh,India,in the year 1991.As many farmers complained us that it has become very difficult task first to rear the Tiger(P.monodon) shrimp post larvae 12(PL 12)in nursery(of 2-3 cents in size)pond and after attaining considerable Stock size, transfer to grown out pond.There was huge number of shrimp larvae or stock size dying due to mishandling or due to change of pond environment etc;In such scenario we ve suggested to all the Shrimp farmers to dug out Nursery pond in grown out pond.First fill water in the nursery,stock pl s and after 20- 30 days of rearing in nursery,gradually increase the water level,so that the complete pond is filled with water.In such pond management no mortality takes place due to mishandling,netting,transferring etc;Thanks to AAN(Photo courtesy)
SPIRULINA CULTURE WRITTEN BY DR.C.GNANESWAR
ORGANIC FISH FARMING.
CRAB CULTURE.
There is a vast scope for crab culture in India.There are 640 species of crabs live in various aquatic environments.Scylla species are considered for culture practices due to their large size nd demand.These are also known as mud crabs,mangrove crabs,green crabs nd brown crabs.Crabs can be cultured in earthen dugout ponds,cages nd tanks.There are two types of rearing 1.Culture 2.Fattening.In culture method crablets are brought from hatcheries or naturally collected from coastal areas ,stocked in and grown for 6-9 months.In fattening method grown up crabs of weighing 50-100 gms are brought from wild,stocked in ponds and fattened till they attain good marketable size.This may take 3-4 months.In Andhra pradesh ,India we can find Crab culture in earthen dug out ponds at Narasapur mandal,West godavary district and in Pitha lava,Nagayalanka mandal,Krishna district.
MURREL CULTURE.
Murrel culture-In India the Channa species are popularly known as Murrels,the snake headed fishes and the mud fishes.The familiarly available species of murrels in India are 1.Channa marulius 2.Channa punctatus and 3.Channa striatus.These are found in freshwater ponds,lakes,canals and rivers.These fishes attain maturity with in 3-6 months of their age and breeds naturally even in confined waters through out the year.The murrels are carnivores and canibalists-the small fishes,insects,zooplanktons and their own breed are the natural foods.The murrels are air breathing fishes,can survive out side the pond environment for 2-4days.This is the reason why these fishes are sold live in the market.The murrels posses vertebral column only and do not contain the spicules or the small bones which makes it easy to eat.The murrel fish meat is considered to be delicacy.The Murrels fetch very high price to that of Carps.The selling price ranges from 600-1000 Rs a kg right at the pond bund.But till to date no large scale or commercial pond culture exists.The reasons for this are 1.these are cannibalists-eats its own breed say for example if we stock 3000 numbers/acre and after certain rearing period go for harvesting we find only 10-30 numbers .So no number,no tonnage.2.These are prolific breeders,breeds through out the year in case stocking density at the begining time of culture is 3000/acre we see lacks of baby murrels and 10-30 harvestable sized murrels at the end of culture period. Again no tonnage ,of course large number will be there.3.Murrels are carnivores eats huge quanitity of animal proteins but their FCR is very HIGH, means eats a lot grows little,thus economically not feasable.Thus the murrels available in the market are naturally caught from the wild and NOT from the culture ponds.Greater research work is essential to establish Murrel culture in ponds.
SEABASS CULTURE
SEABASS culture-The Lates calcarifer is suitable for culture in cages,in earthen dug out ponds with Brackish water or freshwater.It is a fast growing and high yielding variety.The seeds are available in natural resources-the brackish water canals,creeks,estuaries,mangrove swamps and bays.As such induced breeding is succesful the Seabass seeds can be raised in Hatcheries.It is a Carnivorous and Cannibalist-it eats its own breed.Seabass attains 1.5-3kg in first year and 5-6 kgs weight in second year of culture period.In Andhra pradesh,India Seabass are reared in earthen dug out ponds.We can find the culture in Kolleru lake area,the West,East Godavary and Krishna Districts.The Seabass production rates are as high as 25,000-30,000 Kgs/Acre.Where ever Shrimp culture ponds are dug out with 4-8 ft depth,Seabass can be raised an alternate crop for shrimp
SUITABLE SHRIMP SPECIES FOR CULTURE
There are 300 species of shrimps exist in the world waters,out of these P.mondon.,P.idicus,P.merguensis and P.vannamei are already beeing reared in commercial aquaculture ponds.P.monodon are the large sized,highly prefered shrimp in the market,suitable for culture.It was selected as a candidate species for culture in Brackish and freshwater ponds,during the period 1985-1998 or till the occurence of white spot disease.P.vannamei were selected as an alternate candidate species for culture.This candidate species also effected by WSSV,EMS,RMS and some other viral and bacterial diseases,now again farmers are preferring to stock P.monodon species for culture.This is a euryhaline sps,gets acclimatised to wide changes in salinity of water.It must be stocked at a moderate density,fed with well balanced pelleted feed,good pond soil,water management and with suitable,adapted quarentine measures.Let us hope that succesful results will come out.
