Eel is a fish with delicious meat, raising eel will bring high economic value, the fish has a wide adaptability to salinity. They can live in a variety of aquatic environments such as saltwater, brackish, and freshwater. This fish is considered an easy, effective, low-risk species to raise. Next, AgriSearch.net would like to introduce the basic model of raising Eels in earthen ponds for people.
Design and construction of eel ponds
Depending on the actual conditions and production capacity of the household, the eel pond should be arranged accordingly. The best area is about 200-1000m2, so the pond should be sloping towards the drain. Build backup ponds to store water for convenience in water treatment, treatment and supply when necessary.
Choose a pond for raising eels with a bank of 60 cm or more above the water surface and around the pond must be fenced with a net about 50cm high to prevent fish from escaping, and the pond’s banks will not leak or leak. The pond bottom is sandy or muddy sand, the depth is about 1.5 – 1.8m. People should arrange a clay or plastic bladder in the pond so that the fish have a place to live.
Renovating the eel pond
Eel ponds need to be drained, slugs dredged the bottom mud, spread CaCO3 lime (industrial lime) from about 50-100kg/1000m2 depending on soil pH.
Dry the pond bottom for 5-7 days (for areas with potential alum, people should dry for 2 days and then supply water to avoid the phenomenon of alum). Then supply water to fill the eel pond, note that it is necessary to filter the water to a depth of 1.5-1.8m and then treat the pond with potassium permanganate 2-4kg/1000m2.
After about 2 days, we proceed to cause water coloration to stabilize the water quality in the pond, creating an environment suitable for the living habits of the fish.
Apply fertilizer DAP or NPK (soluble in water) with a dosage of 1-2kg/1000m2 dissolved at 8am continuously for 2-3 days until the water is green in color, with a clarity of 30-40cm, p. H: 7.5 – 8.5 is satisfactory.
The remarkable feature is that this fish usually does not like light, so put objects such as crockery pipes, plastic pipes or drop dry scrubs… for them to hide.
Selection and stocking of eels
Breeding: You need to choose to buy fish from reputable breeders. Choose healthy fingerlings, shiny skin, more viscous, no disease. Because the seed source is mainly caught from the wild, we should pay attention to avoid buying fish caught by fishing line, electric pulse … when releasing, the loss rate is very high.
It is possible to select local nursery stock from fry to fish up to about 10 fish/kg, this fish has little loss, high survival rate and is suitable for local conditions.
The best weight of fish stocked from about 5-10 fish/kg is the best.
Stocking density: about 0.5-1 fish/m2.
Transport of fingerlings
By plastic bag with O2 . pump
* Attention :
+ Before transporting, note that for 1 day, do not feed the fish, it is necessary to keep the fish in the stage, put in a place where the water is clear, with a flow to practice 24-26 hours for the fish to get used to the tight environment;
+ Must lower the temperature for fish from 8-10oC, then put in the bag, make the fish in a state of sleep, less activity, the temperature lower slowly, not exceeding 5-8oC at a time.
+ When closing the bag, the density must not exceed 5kg/bag; oxygen is neither too little nor too much which is not good for fish; do not place heavy objects on top of the paper bag; calculate the reasonable transit time for each shipment; if the transportation time is too long, the bag must be opened to change the water, re-inject oxygen; the transit time is too long, the transport density must be reduced accordingly;
+ Transport to the place, drop the plastic bag into the pond so that the temperature inside and outside the bag is equal before opening the bag to let the fish out.
Note before you release, you need to use 1 of 3 chemicals to bathe the fish:
– KMnO4 : 1 – 3 ppm;
– CuSO4: 0.3 – 0.5ppm;
– Formalin: 1-3 ppm.
Or soak the fish in a 15 – 30 % brine solution for 15 – 30 minutes.
The following issues need to be managed:
1. Daily management:
Eel is a new breeder, must regularly monitor the fish’s activity to take timely measures when bad situations occur. It is necessary to observe carefully from the way of feeding to environmental changes (especially pH, toxic gases).
2. Feed management:
Food for eels include worms, snails, trash fish… need to be chopped to fit the fish’s mouth. In order to make fish easier to eat and avoid parasitic diseases from trash fish, it is recommended to dip the fish in salt water, then rinse in fresh water and then feed it to the fish. When the fish is young, the food should be ground to make it easier for the fish to eat. In order to effectively manage food, it is necessary to note the following issues:
– Food needs to be fresh and clean (avoid buying food that has been coated with chemicals).
– You determine a reasonable place to place the floor.
– People keep food not too much (at a water temperature of about 25 oC, the amount of food for a day and night is from 5 to 10% of the total weight of fish in the pond. In case the temperature is lower than 25 oC or higher than 34 oC, then it is necessary to reduce the amount of food in the day. Usually taking the level of fish fed in 1 hour as a standard, adjust the amount of food so that the fish eat all in 1 hour. Because the fish is growing, the amount of food must be increased every 10 days. 1 times.
Depending on the weather, the specific stage, adjust the food accordingly. They often eat strongly on sunny, windy days and reduce their eating on cloudy, rainy days.
– Must be fed on time. Food should not be changed suddenly, but gradually.
– Feed once in a cool morning or afternoon. (Fish feeding floor is a square frame made of iron, the best size is 1m2 wide, 20cm high, stretched with a fishing net)
3. Environmental management of eel farming:
Mainly manage elements:
pH management: should be controlled at 7.5-8.5.
Dissolved oxygen: need to maintain 3mg/l or more
Transparency: cause watercolor or change water to adjust the appropriate clarity 30-40cm.
Temperature: suitable self 25-34 C.
We change the water when we really need it. Because, eels are very sensitive to environmental changes. Each change does not exceed 20% of the water in the pond.
Raising eels is a long process. Especially on hot days, it is best to get water from midnight to early morning to avoid shock due to sudden environmental changes that lead to fish not eating and prone to disease.