PRINCIPLES OF POND FISH CULTURE 1. Fish are dependent for food directly or indirectly on plants. 2. The weight of fish which can be produced in natural waters is dependent upon the ability of the water to raise the plants. We could increase production by adding plant organic matter produced elsewhere. 3. The ability of water to produce plants is dependent upon sunshine, temperature, CO2, Mineral from soil or rocks, nitrogen (NO3- and NH4-) , O2 and water. 4. The Natural fertility of the water is dependent on the fertility of the soil in pond bottom and watershed. 5. Fertlity of water can be increased by adding inorganic fertilizers. 6. After adding all essential minerals and all available nitrogen, the next limiting factor is CO2. This compound can be increased by adding organic matter followed by liming (Ca, Mg). 7. The next limiting factor in fish production, after mineral and CO2 are provided, is oxygen demand of all living and dead organisms in the water. This can be supplied by ru...
Jelawat fish reproduction. Jelawat fish begin spawning at the beginning of the rainy season, which is in October-November. During the rainy season, jelawat able to spawn spawning 2-3 times. When rain and rain water flooded the surrounding area, jelawat began to spawning. The fish are mature gonads migratory into estuaries and perform spawning morning accompanied rintikan rainwater. Jelawat egg is floating. The fertilized eggs were then taken to the water flow downstream and hatch during the trip. Children jelawat measuring 2 cm -3 will arise to the surface of the water and swim in droves along the banks of the river, upstream against the current. While children jelawat size 4- 5 cm glad to be in places that are protected from sunlight that water is rather calm. Jelawat can spawning naturally in ponds, but only spawn at the start of the rainy season. Jelawat fish do not spawn outside the rainy season. To overcome that is then applied to the artificial spawning techniques (induced breedi...
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