Rohu is a type of freshwater fish that is farmed in South Asia. Rohu is a fish species that will grow in predictability if the environmental conditions are correct. When farmers manage the Rohu well, it will grow from a small hatchling to a market sized fish in approximately one year.
Because it takes a Rohu approximately one year to grow to market size, the fish will grow more faster than other species that take longer to reach market size. A growth chart displays the growth journey of the Rohu, and it is useful for farmers because it allows them to see the size of the Rohu at any specific time. If fish farmers use a growth chart, they will be able to identify any problems in the growth of the Rohu before they cost the farmers too much money.
Rohu Growth and Pond Care
For the first few weeks after the hatch, the young Rohu focus on survival. During this time, the growth of the Rohu are slow. Young fry eat the natural plankton in the pond and eventually develop the ability to feed for theirselves.
The young fish grow slow at first because the Rohu are building the structures that will allow the fish to grow quickly in the future. During this time, many farmers may feel impatient with the growth of the young Rohu and begin to overfeed and crowd the young fish in the pond. This can set the growth of the Rohu back.
However, the growth chart show slow growth for these young fish; using the graph, farmers can avoid rushing the growth of the Rohu before they are ready to eat on there own. When the Rohu reach the fingerling stage, they will begin to live in main grow-out ponds. At this time, the growth of the Rohu will increase.
The natural food in the pond will not provide the Rohu with the food they need to grow, so supplementary feed is given to the fish. This supplementary feed may be in the form of pellets or rice bran and oil cake. The growth chart will show the rapid increase in the weight of the Rohu during this stage because the farmers are feeding the Rohu more to promote growth.
Farmers must ensure that the feed provided contains the correct amount of protein and that the daily ration are correct so that money isnt wasted on feeding the Rohu too much. The quality of the water in which the Rohu live will determine the success of the feeding program for the fish. Water quality includes the temperature, the dissolved oxygen levels in the water, and the ammonia content of the water.
All three of these elements affects the growth of the Rohu. If the quality of the water drifts outside of a suitable range for the fish, the growth of the Rohu will slow. Although the growth chart will display the growth of Rohu in optimal water quality, the growth of the Rohu in reality will differ because water quality can range from farm to farm.
Fish farmers must routinely monitor the quality of the water in which the Rohu live. Checking the water quality will help farmers to ensure that the growth of the Rohu continues on the path shown in the growth chart. The stocking density in which the Rohu are kept will affect their growth.
Stocking density is the number of Rohu that are kept in a pond. Some may believe that the more Rohu that are kept in the pond, the more fish will be produced. However, keeping too many Rohu in the pond can lead to reduced growth of each individual fish and the spread of disease among the fish populations.
The growth chart indicates that the fish are grown at sensible stocking densities. If the Rohu are not growing as much as they should, the fish farmer should of inquired whether or not the stocking density of the pond is too high for the aeration and water exchange that the pond is able to provide for the fish. Rohu fish can develop diseases that halt their growth.
These diseases are often caused by bacterial or parasitic infection. If the water quality in the pond is poor for the Rohu or if the fish are frequently handled, their growth will halt because these conditions will stress them out. If fish farmers only pay attention to the weight of the Rohu, they will miss the signs of the growth of the Rohus illnesses.
By using a growth chart and inspecting the health of the Rohu regularly, the fish farmer will be able to treat the diseases quickly to avoid slowing the growth of the remaining fish. If the diseases are not treated, the Rohu will have to grow for several more months to reach the same market size as those that are harvested at a younger age. During the final quarter of the year, the farming ponds almost reach the market-sized size of the Rohu.
Some farmers will choose to harvest the fish at this time to receive their first source of cash for the year. Other farmers will choose to continue to grow the Rohu in the pond so that they can sell the larger fish for more money. The growth chart will be of use to these two scenario because it will allow the farmers to see how much more the fish will weigh after additional months in the pond.
Knowing the additional weight that the Rohu will gain allows the farmers to create a plan for when and how the fish will be harvested. The use of a growth chart allows the farmers to turn their fish farm into a manageable process. Though there is still much to take care of in a fish farm, such as monitoring the water quality, feeding the Rohu, and preventing the growth of diseases, the growth chart will allow the fish farmer to ensure that the fish are of the correct size.
By using a growth chart, the farmer can easily ensure that they are able to achieve the production of Rohu that they aim to create from their pond of fishes.
