The fish cultivation of milkfish belongs to one type of fish contributor of animal protein high enough for human life.
Intensification of cultivation needs to be done, because of low productivity of milkfish with traditional cultivation. Improved cultivation systems should also be followed by the use of new technologies.
1. Biological Properties
Milkfish belongs to the herbivorous fish group, the nation of fish that consume plants. Able to achieve an average weight of 0.6 kg at the age of 5-6 months with intensive maintenance.
The supply of seeds (nener) in sustainability with good quality is done by intensive hatchery system on special pools, namely pematanagn main pond, spawning, peneneraan and pond enlargement. In milkfish hatcheries the steps taken are:
3. Master Selection
The selection of superior parent, the quality of the milkfish puppies is strongly influenced by the mother, the superior milkfish will reduce its properties to keturunananya.
How are the characteristics of the best quality milkfish?
- Normal shape, ideal length and weight ratio.
- The size of the head is relatively small, among the most rapidly growing breeds.
- The arrangement of scales regular, smooth, shiny, no injuries.
- Movement is lively and normal
- Age between 4-5 years.
4. Hormone Injections
Gonadal maturity can be accelerated by the use of LHRH hormone (Letuizing Hormone Releasing Hormone). Spawning is the mixing of mothers and females that have matured sperm cells and egg cells to make the ejaculation of both cells.
Once in the water, sperm cells will fertilize the egg outside the body. Spawning done on spawning pond.
5. Hatching
Eggs that float in spawning ponds hatch after 24-26 hours from the beginning of spawning. Hatching eggs will become larvae that still have food from the parent egg yolk, so it is not necessary to be fed until the age of 2 days.
6. Treating Seeds
After entering the age of 9 days, the larvae are transferred to the nener maintenance pond. In this pond larvae are given natural food in the form of plankton. Plankton growth is done by fertilization and calcification.
Proper fertilization is with TON (ORGANIC NUSANTARA TAMBAK) which contains various essential mineral elements for plankton growth, including N, P, K, Mg, Ca, Mg, S, Cl and others, also comes with humic acid and vulvat which can improve the texture and improve the fertility of the bottom soil pond with a dose of 5 bottles TON / ha or 25 grams (2 tablespoons) / 100 m² in each water entry.
Generation time 8 weeks. Feed given in the form of flour with 30% protein content. To add nutrients to feed mixing fertilizer with NASA with a dose of 2-5 / kg of feed is necessary, because NASA contains essential mineral elements, N, P, K, Mg, Fe, Ca, S and others, vitamins, proteins and fats to promote growth and healthy nener.
7. Magnification.
After being kept in the penenerary pond for 8 weeks, tillers of milkfish are transferred to the enlargement pond.
Technical milkfish enlargement includes several things, namely:
a. Land preparation
This stage is done before the water is inserted. activities undertaken during the preparation of the land are:
- Grounding and reversal of land
aims to free the remaining toxic compounds and toxic gas from decomposition of organic matter from feed or dung. In addition, with soil gemburnya, aeration will run well so that the fertility of the land will increase.
- Calcification
During cultivation, fish require a stable acidity condition that is pH 7-8. To restore the acidity of the soil under these conditions, liming is done because the accumulation and decay of organic matter during the previous cultivation decreases the soil pH.
Calcification also causes bacteria and fungus carriers to die because it is difficult to live on the pH. Calcification with lime tohor, dolomite or zeloit with a dose of 1 TON / ha or 10 kg / 100 m2.
- Fertilization
The main function of fertilization is to provide nutrients necessary for the growth of natural feed, improving soil structure and inhibiting the impregnation of water in porous soil (porosus).
The use of TON for the basic soil fertilization of ponds is very precise, because TONs contain essential mineral elements, and the major organic acids provide the materials necessary for the enhancement of soil fertility and plankton growth.
TON fertilization dose is 5 bottles / ha or 25 gr / 100 square meters.
- Water management. after fertilization with TON, the water is inserted up to 10-20 cm tall then left for several days, to grow the plankton seeds. Water is inserted up to 80 cm or adjust to the depth of the pond.
b. Nener transfer
After the plankton grows (green water color) and brightness as deep as 30-40 cm, the nener in the generating pond is moved to the enlarging pond carefully with adaptation to the new environment.
c. Feeding
In accordance with the nature of milkfish that includes animal herbivores, then these fish like to eat the plants that exist in the pond. The preferred plants of milkfish are moss, algae and clot. To accelerate growth, need to feed the factory, with the standard nutrients needed to grow optimally with protein content of at least 25-28%.
Important diseases that often attack milkfish are:
Decomposition of the fins - caused by bacteria. The symptoms of the fins rot from the edge.
Vibriosis - Caused by bacteria Vibriosis sp, the symptoms of decreased appetite, decay of the fins, and the abdomen are swollen by fluid.
Disease by Protozoa - Symptoms of lost appetite, blind eyes, scaly scales, broken ingsang, lots of slimy.
Disease by Renewal Worms - Often caused by Diploctanum worms that attack the ingsang so it becomes pale and slimy.
Diseases of the bacteria - Parasites and fungi are caused by poor environment, and decreased endurance of fish. Decline in environmental quality is caused by the high pile of organic material and environmental pollution from the river.
Organic materials and dirt will decompose and produce harmful gases. The resilience of the fish is determined by its nutritional consumption. So the way disease control should focus on both factors.
To overcome the environmental degradation can be done TON treatment with a dose of 5 bottles / ha or 25 gr (2 tablespoons) / 100 m2 containing minerals and essential organic acids that can neutralize various gases resulting from pembusuakan dirt in ponds and mineral elements will fertilize plankton as a natural feed.
For the ideal amount of nutrients, it is necessary to feed with the appropriate protein standard and with the addition / mixing of NASA to artificial feed. NASA with the essential minerals, vitamins, organic acids, proteins and fats will supplement and supplement the nutrients of feed, so that the body's resistance to life and growing is always sufficient.
8. Harvest Fish Milkfish
Milkfish harvest can be done in two ways:
Selective Harvest - that is done by draining the pond as much as 70% then shifting with sorted fish nets / selected fish harvested large or fish meet the expected size which then can be brought to the market to sell.
The total harvest can be done simultaneously or at the same time large and small are all harvested and sold to the agent or also to the container.
