PRIYANKA & MADHAVI 8 th B

FISH IS ONE OF THE MOST IMPORTANT SOURCE OF FOOD FOR MAN SINCE SEVERAL THOUSANDS OF YEARS. FISHES ARE THE BEST SOURCE OF PROTIEN AS THEY HAVE 15 TO 25% PROTEIN CONTENT IN THEIR MEAT. FISH MEAT IS ALSO A GOOD SOURCES FOR VITAMIN A AND D ESSENTIAL FATTY ACIDS CALLED UNSATURATED FATTY ACIDS. FISH MEAT IS EASILY DIGESTIBLE PROMOTS GROWTH AND IS HIGH BIOLOGICAL VALUE. GROWING FISHES IN LARGE NUMBERS IS CALLED “PISICULUTURE”. DEPENDING ON THE REGION AND SEASON A WIDE VARIETY OF FISH ARE AVAILABLEIN OUR COUNTRY. FISHES FOUND IN RIVERS, LAKES AND POUNDS ARE CALLED “FRESH WATER FISHES”. FISHES LIVING IN THE SEA ARE CALLED “MARINE FISHES “.

PRIYANKA & MADHAVI 8 th B Scientific nameCommon name Catla catlaBoche Labeo rohitaRohu;Erragandu Cyrrhinus mrigalaErramosu Anabas sarova Cyprinus carpioPedda boche Waluga attuWaluga Tilapia mossambica Channa punctataMatta gidasa FRESH WATER FISHES

PRIYANKA & MADHAVI 8 th B CHANNA PUNCTATA CYPRINUS CARPIO

PRIYANKA & MADHAVI 8 th B LABEO ROHITA TILAPIA MOSSAMBICA

PRIYANKA & MADHAVI 8 th B MARINE FISHES Scientific NameCommon Name Rostrelliger kanagurtakanagurta Sardinella longicepsNune kavallu Horpodon neheriusVanamatta Hilsa hilsaPolasa Lactarius lactariusSudumu ScoliodonSora [Shark] Trichiuris lepturusSavallu [Ribbon Fish]

PRIYANKA & MADHAVI 8 th B ROSTRELLIGER KANAGURTA HORPODON NEHERIUS

PRIYANKA & MADHAVI 8 th B HILSA

PRIYANKA & MADHAVI 8 th B IN OLDEN DAYS, TRADITIONAL METHODS HAVE BEEN EMPLOYED TO CATCH THE FISH THESE OLD METHODS ARE UNABLE TO MEET THEDEMANDS OF EVERINCREASING POPULATION AND OF THE EXPORT MARKETS. NOW-A-DAYS, MODERN METHODS ARE USED TO CATCH THE FISHES LIKE MECHANIZED BOATS, STRONG NYLON NETS. GROWING OF FISHES IN RICE FIELDS IS ALSO MORE COMMON IN VILLAGES. FISH PRODUCTION IS CONSIDERED AS SECOND CROP THE PRIMARY CROP IS RICE FIELDS. TWO MAIN STAGES IN FISH FARMING ARE ; 1.BREEDING & COLLECTION OF EGGS. 2.HATCHING OF EGGS & REARING OF FISH.

PRIYANKA & MADHAVI 8 th B MOST OF THE FISHES DO NOT BREED IN STAGNANT WATER LIKE PONDS, LAKES & RESERVOIRS & PREFER TO BREED IN THEIR NATURAL HABITATFLOWING WATER AS RIVERS. SOME FISHES PRODUCE THOUSANDS OF EGGS WHICH STICK TO EACH OTHER FORMING A LARGE MASS THAT SETTLES DOWN TO THE BOTTOM OF THE RIVER SUCH EGG MASSES CAN BE COLLECTED FROM RIVERS WITH EASE. SOME FISHES PRODUCE EGGS WHICH DO NOT STICK TO EACH OTHER, EACH EGG SETTLES DOWN INDIVIDUALLY ON THE BOTTOM OF RIVER & IT IS DIFFICULT TO COLLECT EGGS. ADULT FISH WHICH ARE READY FOR BREEDING ARE CALLED “BREDERS”. WHEN THE MONSOON SETS IN, THE FISH START BREEDING & THE EGGS ARE LAID IN THE POND, THEY(EGGS) ARE COLLECTED FROM THE POND. OTHERWISE THE EGGS ARE ALLOWED TO HATCH IN THE POND & THE “SPAWN” ARE COLLECTED.

PRIYANKA & MADHAVI 8 th B ADULT FISHES ARE MADE TO BRED IN ARTIFICIAL CONDITIONS IN SPECIALLY DESIGNED CHAMBERS, IS CALLED “INDUCE BREEDING”. INDUCED BREEDING IS THE BEST METHOD TO COLLECT EGGS FROM FISHES & ALSO EXTRACT OF PITUITARY GLAND INJECTED INTO THE FISHES, THEN RELEASED INTO SMALL TANKS WITH FLOWING WATER. PITUITARY EXTRAT INDUCES THE RELEASE OF EGGS FROM FEMALE & SPERMS FROM MALE FISH. AFTER SOMETIME, THE FISHES ARE TAKEN OUT THEIR ABDOMEN IS DRESSED GENTLY & SPERMS(CALLED MILT) & EGGS ARE COLLECTED. THEY ARE TRANSFERRED TO A CLEAN BASIN OF WATER & MIXED WELL TO ALLOW FERTILISATION. AFTER FERTILISATION EGGS ARE COLLECTED THEY ARE TRANSFERRED TO PONDS & ALLOWED TO HATCH.

PRIYANKA & MADHAVI 8 th B EGGS COLLECTED BY THE ABOVE MATHODS MAY BE GROWN IN NATURAL CONDITIONS IN A POND OR IN INCUBATORS. A CONTINOUS SUPPLY OF FLOWING WATER IS MAINTENED. THIS MAINTAINS PROPER OXYGEN LEVELS & HELPS TO REMOVE THE WASTE MATERIAL. SIZE OF THE POND OR INCUBATOR, AMOUNT & CHEMICAL COMPOSITION OF WATER & OTHER CONDITIONS ARE DIFFERENT FOR DIFFERENT TYPES OF FISHES & THEIR EGGS. DEPENDING ON THE TYPE OF FISH, DIFFERENT TIME PERIODS ARE REQUIRED FOR THE EGGS TO COMPLETE THE DEVELOPMENT & YOUNGONES TO HATCH OUT, THAT FISH IS VERY SMALL MEANS “FEW MM” IN LENGTH. THEY TRANSFERRED TO PONDS & MAINTAINEDTILL THEY GROW TO THE REQUIRED SIZE.

PRIYANKA & MADHAVI 8 th B DEPTH METRES AREA HECTARES SIZE OF THE FISH NURSERY POND 1.2 TO 1.5 M0.02 TO 0.8 H 5.6MM -30 MM REARING POND UP TO 2 MUPTO 0.1 H30 MM – 100 MM STOCKING POND 2.5 MUPTO 2. 0 H100 MM TO MAXIMUM SIZE

PRIYANKA & MADHAVI 8 th B THIS IS VERY IMPORTANT AS THE ENTIRE ECONOMY OF THE FISH FARM DEPENDS ON THE SITE WHERE THE POND IS CONSTRUCTED. THE SOIL IN THE POND MUST BE ABLE TO HOLD WATER. AMONG DIFFERENT TYPES OF SOILS, CLAY SOIL IS BEST SUITED AS IT ABSORBS & HOLDS WATER.AN IDEAL SITE FOR A FISH FARM WOULD BE A GENTLY SLOPING LAND WITH HIGH BANKING ON THREE SITES & AN OUTLET ONE SIDE. THIS SAVES A LOT OF EXPENDITURE BY CLOSING OR OPENING OUTLET, WATER CAN BE RETAINED TO THE DESIRE LEVEL OR DEPTH

PRIYANKA & MADHAVI 8 th B