Detailed Explanation of Rice Field Eel Breeding Methods and Technical Points
How to breed rice field eels?
I. Pond Breeding
The rice field eel, also called the long fish, has strong adaptability and vitality and tolerates hunger. It can survive in all kinds of freshwater and is easy to manage. Generally, each kilogram of eel fry can grow into 5-10 kg of adult eels. Artificial breeding of rice field eels occupies little land and water and is highly efficient, making it a path to wealth.
Building the eel pond: Choose a sunny open area, field plot, or old water ditch to build the pond. To make water changes easier, it is best to build the pond where there is a guaranteed water source. Cement ponds, brick ponds, rubble ponds, and lime-sand ponds can all be used, then sealed with cement or lime-sand mortar. The pond bottom and surrounding walls must not leak water and must make it difficult for eels to escape. The size of the eel pond depends on the breeding scale; it can be large or small, from several square meters to several dozen square meters. Generally, the pond is 20-30 sq m, with a depth of about 1 m, and the pond shape depends on the terrain. The water depth is generally kept at around 10-15 cm in spring, summer, and autumn; in winter, drain it dry and leave one rain puddle. To make water changes and drainage easier, open one water inlet and one water outlet at the bottom and top of the eel pond, or install inlet and drainage pipes, and install fish screens. After the pond bottom is built so it does not leak, spread 3-5 cun of mud on it. Mud made from river mud and green grass composted together can be used to line the pond bottom (in some places the pond bottom is lined to a thickness of 60 cm). Place piles of rubble in the center or at the four corners of the pond to help the eels keep warm or cool off, suiting the eels' sedentary habits. The most suitable pond water temperature is 10-25°C. Plant trees, grow melons, plant bamboo to make a shed, or plant several arrowheads around the pond to reduce summer sunlight. Some aquatic plants such as water hyacinth can be planted appropriately in the pond for the eels to escape the summer heat.
Selecting and stocking seed eels: Choose good breeds, with yellow ones being better and green ones second best. It is best to contact eel farmers and buy seed eels of uniform size, strong body, and free of disease and injury; they can also be bought at the market or caught in the wild. Seed eels of about 15-25 per jin are best. Stock them during the third and fourth months after Awakening of Insects (March 5-6). Generally, stock 2.5-3 jin per sq m; if breeding conditions are good, about 5-10 jin can be stocked. When stocking, put one to two toads in each pond for mixed culture, which can help prevent common eel diseases, and put some loofah sponge or straw bundles into the pond so small eels can hide. Seed eels can also be obtained from April to October by catching young eels by hand in rice fields or shallow muddy burrows (or by trapping with cages), but when catching by hand, wear gauze gloves and hold the front half of the eel between the middle and index fingers to avoid injuring the young eels, because young eels caught with iron hooks will have internal injuries and cannot be bred.
Feeding bait: For pond-raised rice field eels, because their range of activity is limited, bait must be provided for intensive culture. The eels that are fed eat supplied river mussel meat, snail meat, small miscellaneous fish and shrimp, livestock and poultry viscera, and borers, silkworm pupae, food factory scraps, and rapeseed cake, and they like artificially bred earthworms and fly maggots. Lights can also be used to attract moths, or pig blood can be used to attract flies to lay maggots as feed. The rice field eel is a carnivorous fish and very greedy. When bait is seriously insufficient, eels may cannibalize each other or eat the small, with the strong eating the weak. Because eels do not come out to activity during the day, it is best to feed them between 8 and 10 p.m. each day. Animal bait should be the main feed, with plant bait (such as bran, rice, and sweet and sour foods like melons and fruit) as a supplement. Generally feed once a day. In the early stage, the feeding amount is 3-5% of the eels' body weight, and as the eels' body weight increases, the feeding amount increases accordingly. It is best to scatter the bait evenly over the whole pond. When bait is insufficient, some duckweed and mulberry leaves can also be fed as a supplement. Seize the golden season for eel growth from after spring to before winter and feed at the right time. To avoid the eels stopping feeding, mixed feed is required. The principles of feeding are freshness, nutrition, variety, and complete consumption. Human and livestock manure must be rotted and fermented before being splashed on for feeding. It is strictly forbidden to use sour, spoiled, moldy, putrid, or deteriorated foods such as distillers' grains, tofu residue, and potato residue. If feeding is done at fixed times and fixed places, it makes it easier for the eels to eat and for manual harvesting. On the morning after feeding, clear away leftover bait or add fresh eel pond water to keep more oxygen in the pond. Of course, feeding must also be moderate; too much will make the water quality deteriorate, while too little will leave insufficient food.
Careful management: Management should follow the "three checks and three preventions." First, check the water conditions, keep the water quality fresh and clean, and keep the pond clean and sanitary. Observe frequently. If the water smells slightly foul or is abnormal, change the water immediately. Where the water source is poor, change the water once every 5-8 days; change frequently with the seasons. In hot weather when the water temperature is too high, also build a shade shed for cover or appropriately deepen the water level. In winter, try not to change the water. Some loaches can be mixed into the pond. Stock 1-2 jin per sq m to improve water quality and prevent the eels from tangling around each other. Second, check the bait conditions, paying attention to observations of bait shortage, single bait, and mixed bait, and note that during thunderstorms and rain and when bait is lacking, the eels may be startled and escape outward, not eat, and not enter their burrows; when bait is lacking, eels may chase the large after the small and attack each other. When changing to new bait, go from less to more. Third, check for disease; as long as prevention is done in advance and observation is careful, eel diseases can be controlled.
The "three preventions" are: First, prevent escape. The pond must be built firmly to prevent floods from washing away the pond or the eels from climbing over the pond; during thunderstorms, drain water to prevent escape. Second, prevent harm; geese and ducks must not enter the pond. Third, prevent poisoning; it is strictly forbidden for cigarette butts, chemical fertilizers, pesticides, or polluted water to enter the pond. Chemical fertilizers and pesticides in particular are highly lethal to fish. Once poisoning is discovered, thoroughly drain the pond water and use fresh water to flush out the toxic water and pollutants in the pond. Then mash garlic and mix it with water, applying 5 grams per sq m into the pond, to avoid massive eel deaths.
Disease prevention and treatment: Common rice field eel diseases include fever disease, cold disease, skin poison disease, and capillary nematode disease. Fever disease is caused by too high a density of eels. The prevention and treatment method is to mix a small amount of loach into the pond (preferably 1 loach for every 200 eels). When the eels become diseased, change the water immediately, or add a 7-in-10,000 copper sulfate solution to the pond, splashing about one large liang per sq m. Eel cold is caused by the new water added being too low in temperature. Before changing water with very low-temperature spring water, well water, mountain mineral water, or reservoir water, let the water temperature rise before putting it into the pond. In late autumn and early winter, when the water temperature drops below 12°C, the eels begin to enter the mud at a depth of about 30 cm to spend the winter. At this time, drain the pond water, keep only the mud moist, and cover the mud with a layer of straw about 5 cun thick to prevent freezing and avoid ice formation. The appearance of plum-blossom spots the size of soybeans or broad beans on the backs of the eels is a common disease of rice field eels. The preventive method is to frequently put some toads into the eel pond, because the secretions on the toads' bodies have the effect of preventing this disease. If the eels already have this disease, immediately take 1-2 skinned toads, tie them with string, and drag them through the pond a few times, and the disease can be cured. Skin poison disease is caused by mold infection after eels bite each other or are attacked by harmful organisms, causing wounds. Sick eels grow "white hair" on the body, lose appetite, become thin and weak, and die. Before the eels are put into the pond, quicklime should be used to clear the pond and disinfect it. If sick eels are found, a mixture of 4-in-10,000 salt and baking soda can be splashed over the whole pond. In the early stage of eel breeding, they are prone to saprolegniasis, which can be treated by applying 5% iodine tincture to the affected area or soaking in 3-5% salt water for 3-4 minutes. Rice field eel capillary nematode disease is caused by capillary nematodes parasitizing in the eels' intestines, damaging the intestinal wall tissue, causing inflammation of the intestinal wall and leading to weight loss and death of the eels. Quicklime should also be used to clear the pond and kill the eggs before eel breeding. If this eel disease is found, for every 100 jin of eels, use 5 grams of 90% trichlorfon crystals mixed into 3 jin of soybean cake powder, make medicinal pellets, and feed them
Reproduction and storage and transport: The rice field eel has the characteristic of sex reversal. From embryo to first sexual maturity, it is female. Rice field eels begin sexual maturity at two months of age. The fish body is first female and later male. When the body length is about 10 cm, it is generally female. When it grows to about 5 cm, it lays eggs for the first time, and afterward sex reversal gradually occurs. When the body length reaches about 35 cm, males and females each account for half. When the body length is above 53 cm, they are all male. The reproductive season of rice field eels is April-August, with the peak spawning period in May-June. Grain leaves should be placed in the pond to facilitate spawning. Generally, after about 7 days, the eggs naturally hatch into young eels. Leaves with eggs stuck to them should be placed in another eel pond so that after hatching they can be fed with fine feed. To prevent adult eels and water rats from harming the young eel fry, during the reproduction period the loofah sponge and straw bundles placed in the pond cannot be removed, so that the young eel fry can take shelter. If eel fry are stored and transported properly, the survival rate can reach over 90%. The method is to disinfect the bamboo baskets and line them with mold-free film. Put about 50 jin in each basket. Do not put water in the basket and do not seal the opening, to prevent oxygen deficiency. Put an appropriate amount of soapy mud in the basket. Each day, break 4 eggs per basket, stir them evenly, and pour them into the basket, stirring them apart by hand to maintain a certain amount of nutrients and moisture. Put 1-2 jin of loach in each basket. Every 12 hours, insert a hand into the basket and stir to prevent the eels' bodies from overheating.
When catching rice field eels, take the large ones and leave the small ones, keeping enough seed stock in the pond for continued breeding. It is best to use the hook-fishing method, that is, put an earthworm on the hook and extend it into the eel burrow to catch them. You can also use a net to catch them 1-2 times first, then drain the water and catch them, and after catching, wash them clean with fresh water. The net used to catch rice field eels is generally the summer-fry net used for catching fish fry. When the rice field eels are hibernating, you can turn over the soil to catch them.
The rice field eel, also called the long fish, has strong adaptability and vitality and tolerates hunger. It can survive in all kinds of freshwater and is easy to manage. Generally, each kilogram of eel fry can grow into 5-10 kg of adult eels. Artificial breeding of rice field eels occupies little land and water and is highly efficient, making it a path to wealth.
Building the eel pond: Choose a sunny open area, field plot, or old water ditch to build the pond. To make water changes easier, it is best to build the pond where there is a guaranteed water source. Cement ponds, brick ponds, rubble ponds, and lime-sand ponds can all be used, then sealed with cement or lime-sand mortar. The pond bottom and surrounding walls must not leak water and must make it difficult for eels to escape. The size of the eel pond depends on the breeding scale; it can be large or small, from several square meters to several dozen square meters. Generally, the pond is 20-30 sq m, with a depth of about 1 m, and the pond shape depends on the terrain. The water depth is generally kept at around 10-15 cm in spring, summer, and autumn; in winter, drain it dry and leave one rain puddle. To make water changes and drainage easier, open one water inlet and one water outlet at the bottom and top of the eel pond, or install inlet and drainage pipes, and install fish screens. After the pond bottom is built so it does not leak, spread 3-5 cun of mud on it. Mud made from river mud and green grass composted together can be used to line the pond bottom (in some places the pond bottom is lined to a thickness of 60 cm). Place piles of rubble in the center or at the four corners of the pond to help the eels keep warm or cool off, suiting the eels' sedentary habits. The most suitable pond water temperature is 10-25°C. Plant trees, grow melons, plant bamboo to make a shed, or plant several arrowheads around the pond to reduce summer sunlight. Some aquatic plants such as water hyacinth can be planted appropriately in the pond for the eels to escape the summer heat.
Selecting and stocking seed eels: Choose good breeds, with yellow ones being better and green ones second best. It is best to contact eel farmers and buy seed eels of uniform size, strong body, and free of disease and injury; they can also be bought at the market or caught in the wild. Seed eels of about 15-25 per jin are best. Stock them during the third and fourth months after Awakening of Insects (March 5-6). Generally, stock 2.5-3 jin per sq m; if breeding conditions are good, about 5-10 jin can be stocked. When stocking, put one to two toads in each pond for mixed culture, which can help prevent common eel diseases, and put some loofah sponge or straw bundles into the pond so small eels can hide. Seed eels can also be obtained from April to October by catching young eels by hand in rice fields or shallow muddy burrows (or by trapping with cages), but when catching by hand, wear gauze gloves and hold the front half of the eel between the middle and index fingers to avoid injuring the young eels, because young eels caught with iron hooks will have internal injuries and cannot be bred.
Feeding bait: For pond-raised rice field eels, because their range of activity is limited, bait must be provided for intensive culture. The eels that are fed eat supplied river mussel meat, snail meat, small miscellaneous fish and shrimp, livestock and poultry viscera, and borers, silkworm pupae, food factory scraps, and rapeseed cake, and they like artificially bred earthworms and fly maggots. Lights can also be used to attract moths, or pig blood can be used to attract flies to lay maggots as feed. The rice field eel is a carnivorous fish and very greedy. When bait is seriously insufficient, eels may cannibalize each other or eat the small, with the strong eating the weak. Because eels do not come out to activity during the day, it is best to feed them between 8 and 10 p.m. each day. Animal bait should be the main feed, with plant bait (such as bran, rice, and sweet and sour foods like melons and fruit) as a supplement. Generally feed once a day. In the early stage, the feeding amount is 3-5% of the eels' body weight, and as the eels' body weight increases, the feeding amount increases accordingly. It is best to scatter the bait evenly over the whole pond. When bait is insufficient, some duckweed and mulberry leaves can also be fed as a supplement. Seize the golden season for eel growth from after spring to before winter and feed at the right time. To avoid the eels stopping feeding, mixed feed is required. The principles of feeding are freshness, nutrition, variety, and complete consumption. Human and livestock manure must be rotted and fermented before being splashed on for feeding. It is strictly forbidden to use sour, spoiled, moldy, putrid, or deteriorated foods such as distillers' grains, tofu residue, and potato residue. If feeding is done at fixed times and fixed places, it makes it easier for the eels to eat and for manual harvesting. On the morning after feeding, clear away leftover bait or add fresh eel pond water to keep more oxygen in the pond. Of course, feeding must also be moderate; too much will make the water quality deteriorate, while too little will leave insufficient food.
Careful management: Management should follow the "three checks and three preventions." First, check the water conditions, keep the water quality fresh and clean, and keep the pond clean and sanitary. Observe frequently. If the water smells slightly foul or is abnormal, change the water immediately. Where the water source is poor, change the water once every 5-8 days; change frequently with the seasons. In hot weather when the water temperature is too high, also build a shade shed for cover or appropriately deepen the water level. In winter, try not to change the water. Some loaches can be mixed into the pond. Stock 1-2 jin per sq m to improve water quality and prevent the eels from tangling around each other. Second, check the bait conditions, paying attention to observations of bait shortage, single bait, and mixed bait, and note that during thunderstorms and rain and when bait is lacking, the eels may be startled and escape outward, not eat, and not enter their burrows; when bait is lacking, eels may chase the large after the small and attack each other. When changing to new bait, go from less to more. Third, check for disease; as long as prevention is done in advance and observation is careful, eel diseases can be controlled.
The "three preventions" are: First, prevent escape. The pond must be built firmly to prevent floods from washing away the pond or the eels from climbing over the pond; during thunderstorms, drain water to prevent escape. Second, prevent harm; geese and ducks must not enter the pond. Third, prevent poisoning; it is strictly forbidden for cigarette butts, chemical fertilizers, pesticides, or polluted water to enter the pond. Chemical fertilizers and pesticides in particular are highly lethal to fish. Once poisoning is discovered, thoroughly drain the pond water and use fresh water to flush out the toxic water and pollutants in the pond. Then mash garlic and mix it with water, applying 5 grams per sq m into the pond, to avoid massive eel deaths.
Disease prevention and treatment: Common rice field eel diseases include fever disease, cold disease, skin poison disease, and capillary nematode disease. Fever disease is caused by too high a density of eels. The prevention and treatment method is to mix a small amount of loach into the pond (preferably 1 loach for every 200 eels). When the eels become diseased, change the water immediately, or add a 7-in-10,000 copper sulfate solution to the pond, splashing about one large liang per sq m. Eel cold is caused by the new water added being too low in temperature. Before changing water with very low-temperature spring water, well water, mountain mineral water, or reservoir water, let the water temperature rise before putting it into the pond. In late autumn and early winter, when the water temperature drops below 12°C, the eels begin to enter the mud at a depth of about 30 cm to spend the winter. At this time, drain the pond water, keep only the mud moist, and cover the mud with a layer of straw about 5 cun thick to prevent freezing and avoid ice formation. The appearance of plum-blossom spots the size of soybeans or broad beans on the backs of the eels is a common disease of rice field eels. The preventive method is to frequently put some toads into the eel pond, because the secretions on the toads' bodies have the effect of preventing this disease. If the eels already have this disease, immediately take 1-2 skinned toads, tie them with string, and drag them through the pond a few times, and the disease can be cured. Skin poison disease is caused by mold infection after eels bite each other or are attacked by harmful organisms, causing wounds. Sick eels grow "white hair" on the body, lose appetite, become thin and weak, and die. Before the eels are put into the pond, quicklime should be used to clear the pond and disinfect it. If sick eels are found, a mixture of 4-in-10,000 salt and baking soda can be splashed over the whole pond. In the early stage of eel breeding, they are prone to saprolegniasis, which can be treated by applying 5% iodine tincture to the affected area or soaking in 3-5% salt water for 3-4 minutes. Rice field eel capillary nematode disease is caused by capillary nematodes parasitizing in the eels' intestines, damaging the intestinal wall tissue, causing inflammation of the intestinal wall and leading to weight loss and death of the eels. Quicklime should also be used to clear the pond and kill the eggs before eel breeding. If this eel disease is found, for every 100 jin of eels, use 5 grams of 90% trichlorfon crystals mixed into 3 jin of soybean cake powder, make medicinal pellets, and feed them
Reproduction and storage and transport: The rice field eel has the characteristic of sex reversal. From embryo to first sexual maturity, it is female. Rice field eels begin sexual maturity at two months of age. The fish body is first female and later male. When the body length is about 10 cm, it is generally female. When it grows to about 5 cm, it lays eggs for the first time, and afterward sex reversal gradually occurs. When the body length reaches about 35 cm, males and females each account for half. When the body length is above 53 cm, they are all male. The reproductive season of rice field eels is April-August, with the peak spawning period in May-June. Grain leaves should be placed in the pond to facilitate spawning. Generally, after about 7 days, the eggs naturally hatch into young eels. Leaves with eggs stuck to them should be placed in another eel pond so that after hatching they can be fed with fine feed. To prevent adult eels and water rats from harming the young eel fry, during the reproduction period the loofah sponge and straw bundles placed in the pond cannot be removed, so that the young eel fry can take shelter. If eel fry are stored and transported properly, the survival rate can reach over 90%. The method is to disinfect the bamboo baskets and line them with mold-free film. Put about 50 jin in each basket. Do not put water in the basket and do not seal the opening, to prevent oxygen deficiency. Put an appropriate amount of soapy mud in the basket. Each day, break 4 eggs per basket, stir them evenly, and pour them into the basket, stirring them apart by hand to maintain a certain amount of nutrients and moisture. Put 1-2 jin of loach in each basket. Every 12 hours, insert a hand into the basket and stir to prevent the eels' bodies from overheating.
When catching rice field eels, take the large ones and leave the small ones, keeping enough seed stock in the pond for continued breeding. It is best to use the hook-fishing method, that is, put an earthworm on the hook and extend it into the eel burrow to catch them. You can also use a net to catch them 1-2 times first, then drain the water and catch them, and after catching, wash them clean with fresh water. The net used to catch rice field eels is generally the summer-fry net used for catching fish fry. When the rice field eels are hibernating, you can turn over the soil to catch them.