Goby fish is always a favorite seafood in the consumer market. That is also the reason why many households want to implement the goby farming model with high economic efficiency. In order to produce a large goby, farmers need to understand the rules and regulations Goby fish farming technique. The content of today’s article will help you better understand this topic.
Prepare the pond
The pond must be located in an area that is not contaminated with alum, loamy soil or clay soil to retain water for a long time. The pond is near the water source, near the house for easy monitoring and care. Around the pond must be cool, not shady, with plenty of light.
For easy care and management, it is best to choose a pond with an area of 200-500 m2. The water depth is from 1.2 to 1.5 m. The pond bank is about 0.5 m higher than the highest pond water level to prevent flooding.
The pond has separate supply and drainage culverts, the diameter of which is about 20-30 cm. At the outer and inner culverts must be covered with nets to prevent fish from going out and predators entering the pond. The pond bank is firm, the pond bottom is flat and slopes towards the drain. The bottom layer of mud is about 20 cm thick for fish to hide in. There are soils for the ponds with bamboo tubes, clay pots, tree stumps, etc. for fish to hide.
The water supply to the pond must be clean, unpolluted by domestic waste and waste from industrial plants, and be proactive throughout the farming process. Requirements for water quality are as follows: pH = 6.5-7.5; temperature = 28-30°C; dissolved oxygen content above 4 mg/liter.
Pond improvement: Pond conditions greatly determine the development of fish. Therefore, before stocking fish, it is necessary to improve the pond carefully to help the fish grow well and limit diseases. The pond improvement process is as follows:
+ Clean up the coastal vegetation. Drain the pond water and clean up the garbage, catch all trash fish and predators (such as snakes, crabs, frogs…). Fish medicinal plants can be used to kill impurities, by: draining the pond water, then smashing the fish medicinal plants and diluting it with water and then watering all over the pond, dosage: 1 kg of fish medicinal roots for 100 m2 of water).
+ Dredging the long-term rotten mud layer at the bottom of the pond, leaving only a layer of mud about 20 cm. Renovate pond banks and sewers. Filling holes for leaks.
+ Spread lime powder to the bottom of the pond and around the pond to kill bacteria and adjust the pH, dosage: 10-15 kg / 100 m2. Then dry the pond in the sun for about 3-4 days and then fertilize the pond.
+ Fertilization is to color the water and create a natural food source. You can apply manure or inorganic fertilizer, but it is best to apply manure to keep the water color longer.
Fertilizer: Can use manure of chickens, ducks, pigs … composted; Dosage: 25-30 kg/100 m2 pond; How to fertilize: spread fertilizer evenly throughout the pond bottom.
Inorganic fertilizers: Apply urea and phosphate fertilizers, dosage: 0.5 kg urea + 0.3 kg phosphorus/100 m2 pond.
+ After fertilizing, take water into the pond to reach the specified level. After about 3-4 days, the pond water turns green, which means that the natural food source in the pond has begun to proliferate and is enough to supply the fry in the first few days. At this time, the fish can be released.
Previously, when the breed of goby fish could not be produced, farmers often bought fingerlings from wild-caught sources, the quality of this fish source was not guaranteed. Currently, the source of fingerlings has been active because there are many establishments producing fingerlings. However, farmers need to know how to choose good quality fingerlings so that they grow quickly and bring high efficiency.
The following are the criteria for selecting fingerlings:
- The fingerlings are uniform in size, about 100-150 g/fish. The fish is healthy, no cuts, no loss of viscosity, no signs of disease, no deformities or deformities.
- The fish swims quickly, the fins spread wide. Fins and scales intact. When flipping the fish upside down, you can see that the gills are really big, the tail and the rays are spread out to the fullest.
- The fish is not red in the belly and navel. If the belly of the fish is red and swollen, the fish may be infected with parasites.
- Stocking density depends on ponds with static water or ponds with circulating water.
- Ponds without circulation: raise from 2-3 fish/m2.
- Circulating ponds: raise 4-5 fish/m2.
- Ponds with continuous circulation: raise 8-10 fish/m2.
Before releasing into the pond, it is recommended to bathe the fish with 2% salt water for a few minutes to kill pathogens. In case the fingerlings are stored in plastic bags, they must be soaked in the pond water for about 10-15 minutes so that the water temperature in the bag is equal to the pond water temperature, then open the bag and release the fish slowly. In case the fingerlings are kept in plastic containers or cans, they must be put in a large pot and then slowly add pond water to the pot to balance the water in the pot with the pond water. After 10-15 minutes, the fish should be released into the pond.
Fish should be released in the cool of the day, preferably in the early morning or evening.
Note: If you are cautious, do not immediately release the fingerlings into the pond, but put the net in a corner of the pond, raise it for about 10 days, and feed it with both quantity and quality. After 10 days, check the fish, remove the weak ones, then open the net to let the fish into the pond.
Feed, care and manage, harvest
The main food of fish is fresh animals such as juveniles, shrimp, shrimp, snails, crabs, earthworms, etc. The food must be clean and not stinky. Plant foods should not be used.
Feed at least twice a day, early morning and evening. The amount of daily feed equals 5-7% of the total weight of fish in the pond (100 kg of fish fed 5-7 kg of feed/day). The larger the fish, the smaller the amount of food.
In the first month, the food should be crushed and mixed with rice flour to make it easier for the fish to eat. In the following months, simply chop the food to fit the fish’s mouth. Should adjust the amount of food enough during the day, if there is excess, discard, not to the next day.
To minimize feed loss as well as for ease of control, feed should be placed on the floor and placed in multiple locations in the pond. The floor is about 0.5-0.6 m from the water surface, with a strap for easy pulling up and down. After 1 hour of feeding, pull the floor up to check whether the food is still or not to adjust the dose accordingly.
Note that you have to give food slowly, when you see all the food on the floor, then give it again. Do not give too much food, because the fish does not eat all of it, it will waste and pollute the water. It is necessary to monitor the fish’s baiting behavior and check the amount of food in the floor to adjust accordingly, avoiding the case of excess or lack of food. If there is a lot of leftover food on the floor, it must be removed to avoid contaminating the water, and next time, reduce the dose. Before feeding the fish, make sure the floor is clean and then put the food in.
Regularly supplement with vitamin C and mineral premix to help fish strengthen disease resistance. The amount of vitamin c and Premix accounts for about 2%.
Care and management
After each feeding day, check the food residue in the floor and clean the floor.
Periodically change the type of food to stimulate the fish’s appetite and grow quickly.
The pond water must be changed regularly to maintain water quality, remove dirty water and dirt. Change the water once a day, about 20% of the pond water each time.
Regularly monitor pond water color, maintaining pond water with young banana green color is the best. When you see that the water is too dark green, gray or has a bad smell due to algae or decaying food, you must change the water immediately. When withdrawing, use a net to prevent the fish from escaping. Water entering the pond must pass through a net to prevent trash fish and predators. When the pond water level drops low, water must be added to the original water level. Water entering the pond must be controlled to flow slowly to avoid panicking the fish.
Create conditions for fish to catch prey both during the day and at night, by releasing water hyacinth and plants around the edge of the pond as a place for fish to hide and catch prey.
Fish have the habit of burrowing in the mud and burrows, so they are susceptible to parasites. To prevent this disease, periodically treat pond water with chemicals, or bundle the leaves into small bundles and put them in the bottom of the pond.
Regularly check pond banks and sewers to promptly overcome landslides and leaks.
Regularly monitor the activities of fish, if there are any abnormal signs, they must immediately check for timely handling.
Periodically (about once every 10 days) use powdered lime mixed with water and sprinkle it all over the pond to kill pathogens, dosage: 5-6 kg of powdered lime/100 m2.
Periodically (about once every 15 days) catch a few fish to check the growth rate in length and weight, thereby estimating the total weight of fish in the pond and as a basis for calculating the appropriate amount of food.
After 7-8 months of rearing, the fish reaches a size of 400-500 g/fish. At this time, fish can be harvested. You can collect the big ones first, then collect all of them at the end of the season. Goby often burrow into the mud, so harvesting is more difficult than other fish species.
The content of this article is the technique of raising goby fish that AgriSearch.net wants to share. Hopefully through the article, farmers can easily build a suitable model of goby farming for themselves.