Shing farming: how to raise the stinging catfish profitably

Live shing in a market basket stops shoppers in their tracks. It costs more than many other fish, yet demand never falls. It is prized as food for the sick and just as popular on the plates of the healthy. That demand is why farming the stinging catfish (shing) has become a popular and profitable venture in Bangladesh. With the right method, care and modern techniques, shing production can be made to pay well, and a farmer who starts by the rules can turn it into one of a household's main sources of income.

Native shing, also called jiol, was once abundant in our canals and beels. When the monsoon waters receded, a hand in the mud of a ditch would come up with shing. For various reasons that abundance has gone. Shing used not to be farmed in ponds at all; the wild catch was the only source. As its natural habitat shrank, the fish came close to disappearing.

Artificial breeding changed that. Fish farmers in Bangladesh have mastered inducing broodfish to spawn in hatcheries with hormone injections and raising fry from the eggs. Published research on hatcheries in the Jessore region describes shing being bred with pituitary gland extract. By producing fry this way, farmers have saved the fish from extinction.

The Dhala area of Trishal upazila in Mymensingh is a leading example. According to a report by the Agricare desk, fish farmers there have become financially secure by raising native shing. They have shown that a small pond of one decimal can earn 50,000 to 60,000 taka every six months. Around fish farming, 35 hatcheries have grown up in Dhala. At least 500 families are directly involved in fish farming, and some 10,000 people have found work.

Their success has opened the way for interested farmers elsewhere, and because the fish pays, its culture is spreading year by year. If the small village ponds and abandoned ditches that lie idle across the country were brought under shing, production of the fish could be transformed.

Some traits make shing especially suited to small farmers. A pair of long air sacs runs back from its gill chambers along either side of the body, allowing it to breathe air directly. That is why shing survives in oxygen-poor ditches, pools and drying channels where rohu and catla cannot live.

As a farmed fish, its advantages are:

• High market price: native shing is always in demand and fetches a good price.
• Little space: it can be raised in ditches, small abandoned ponds and planned ponds alike.
• Hardiness: it lives on less feed than other fish and copes with ordinary adverse conditions.
• Nutrition: shing is rich in protein and other nutrients.
• Reliable seed: fry can be produced in hatcheries, and the fish quickly takes to supplementary feed.
• Flexibility: it can be farmed on its own or together with other species.
• Quick returns: with the right feed and care it reaches market size in a short time.

Several points need particular attention when choosing a pond for shing. On rainy nights this fish can climb out over the bank and even travel across wet ground to another water body, so the pond's structure matters more than it does for other fish.

• The pond must be free from flooding.
• The banks must be strong. If there is any hole in the bank, the shing will all escape through it.
• Choose a pond whose water will not rise above 4 feet even during monsoon rain.
• Experience shows that rectangular ponds give better results: with the same feed and management, a rectangular pond produces at least 10 per cent more than a square one.
• An area of 30 to 50 decimals is best, and one end of the pond should be 1 foot lower than the other, to make draining and harvesting easier.

The importance of that last point, the slope, becomes clearest at harvest time. More on that later.

Ponds of 30 to 50 decimals generally suit shing best, though a one-acre pond can also be used. The first job is to pump the pond dry and let the sun reach the bottom, which drives off much of the harmful organisms and gas in the mud. For a newly dug pond, this is the time to shape it and set the slope as required.

If the pond cannot be dried, unwanted and predatory fish must be removed with rotenone while it is still full. If snakeheads, spotted snakeheads or wallago remain, the young shing become their food.

The main preparation then begins with lime at 1 kilogram per decimal. Lime corrects acidity and reduces disease organisms. The original report says that applying 250 grams per decimal of a granular product (sold as Shing Bright Gold) after liming keeps the water colour stable. Then 5 kilograms of cow dung, 100 grams of urea and 50 grams of TSP per decimal are dissolved together and spread over the pond. This fertiliser grows natural food in the water, the tiny plants and animals called plankton. Five to six days after fertilising, shing fry of 2 to 3 inches can be stocked.

Once the pond is ready, stock fry of about 2 inches from a hatchery known for quality. Fry production technology is now widespread in the country and many hatcheries produce shing fry. But most do not know how fry should be stocked to keep deaths low, or what follow-up management is needed, and so heavy mortality often follows stocking.

The remedy is to protect the fry in three stages. First, after netting at the hatchery, the fry should be conditioned, held for a while in clean water to recover from the stress, and given a bath in an anti-fungal medicine before delivery. Second, after transport, they should be bathed in anti-fungal medicine again before release into the pond; otherwise they may develop ulcer disease after stocking. Third, two to three days after release, the pond should be treated again with a similar medicine. Done this way, the risk of disease after stocking falls sharply.

Very small fry from the hatchery are better nursed in a separate nursery pond until they reach 2 to 3 inches before moving to the grow-out pond. During nursing, 2 to 2.5 feet of water is enough.

In monoculture, 500 to 1,000 shing fry can be stocked per decimal. That is a high number, so water quality must be protected before and after stocking. If there is no way to change the water, stocking fewer is better; the denser the stock, the greater the risk of the water going bad.

In mixed culture, shing does well with magur (walking catfish) and koi (climbing perch). All three can breathe air and survive in relatively little water, so they sit well together. Either way, quality, healthy fry are essential.

Shing eats the insects and small creatures at the pond bottom, but profitable farming requires a quality supplementary feed with at least 32 per cent protein. Factory-made quality feed is best. Shing can also be raised on good floating feed, which has an added benefit: because the pellets float, uneaten feed does not sink and rot, and the pond bottom stays healthy.

From stocking onwards, feed regularly and in measured amounts, dividing the day's ration into two or three meals. Farmers who make their own feed must use good fishmeal rather than meat and bone meal as the animal protein. The original report says that adding a digestive enzyme (Biozyme) and a growth promoter (Rapid Grow) to the feed gives very good results. In short, shing farming does not pay without quality feed.

A practical way to get the ration right is to feed at a few fixed spots in the pond and check after a while whether the feed has gone. If some is left every time, the ration is too large and should be cut at the next meal. On cloudy days or in a sudden cold spell the fish eat less, and feeding less is again the safe course. Writing down how much feed goes in each day makes it easier to match costs against growth at the end of the month.

Shing culture can start in April and May. Farmers who hold fry over in nursery ponds from late in the previous year can begin planned culture from the end of February. Fry are most readily available from May and June each year.

With quality fry, balanced feed and good management, each shing reaches 60 to 70 grams in six to seven months. If water quality is kept at ideal levels throughout, even better results can be expected.

Shing does not need much water: 2 to 2.5 feet during nursing and 3 to 3.5 feet afterwards are enough. But while the quantity can be small, there is no compromise on quality. Shing growth is directly linked to the water quality and the condition of the pond bottom.

The original report advises applying a probiotic product (Aqua Magic Plus) once a month to help keep the bottom and the water in good condition. Probiotics are beneficial microbes that help break down organic waste on the pond floor.

Another old technique is to keep some water hyacinth inside a bamboo enclosure in the pond or along one side. It makes the water more suitable for shing, which find shade and shelter under the roots, and the enclosure stops the hyacinth from covering the whole pond.

Sometimes cotton-like white patches appear on the skin and lips of the fry. A fungus called Saprolegnia is responsible. According to the original report, 500 to 600 millilitres of Polguard Plus per acre for every 3 feet of water, applied as two doses on two consecutive days, gives good results. Formalin or malachite green can also be used, though malachite green is banned for use on food fish in many countries, so it is important to consult the upazila fisheries officer before using it. For parasites or protozoa, a suitable antiparasitic treatment works well.

The worst enemy of shing farming, however, is not a microbe but ammonia gas. Overfeeding or rotting organic matter raises ammonia levels in the water, and fish can then die very quickly. According to the original report, spreading 300 to 400 grams of Gasonex Plus per acre, mixed with sand, over the whole pond gives immediate relief, and changing some water at the same time helps further. That is why controlling feed quantity matters so much: extra feed does not add profit, it adds danger.

For disease prevention, a monthly routine is recommended from the second month of culture: Polguard Plus or Pond Safe in the first week of each month, Gasonex Plus in the second week and Aqua Magic Plus in the third. Alongside this, the fish should be netted and checked from time to time. The dose of any medicine is safest when set by the label together with the advice of the local fisheries office.

Other fish can be caught by dragging a net, but not shing: it burrows into the mud and escapes under the net. To catch shing, the pond has to be pumped dry towards the end of the night. The best time to catch them is from dawn to 8 in the morning; catching them once the sun is up risks killing the fish.

If not all the fish can be caught in a day, the pond should be refilled with at least 2 feet of cool water using a shallow pump, and the fish caught the same way the next day. The technique is distinctive: with a plastic noodle strainer in one hand and a small steel bowl in the other, the fish are scooped into a large plastic container and then released into a hapa, a fine-mesh net cage suspended in water.

This is where the pond's slope pays off. If one side is lower, all the fish gather at the low end once the pond is drained. Without a slope they stay scattered in the mud across the whole pond and are very hard to catch.

Care is needed when catching shing. There are venom glands at the base of the spines in its pectoral fins, so a sting is extremely painful. Applying a pain-relieving ointment to the spot and a hot-water compress gives some immediate relief; ointment followed by a warm sand compress also helps. It is worth having these at hand before harvesting, though with a little care they are rarely needed.

The air sacs help the farmer at the point of sale too. Because it can breathe air, shing stays alive for a long time in very little water, and live shing fetches the best price in the market. It pays to hold the catch in a hapa for a while so the fish recover from the stress, then send them to market in containers with a little water. Dead or injured fish sell for much less, so the whole process of catching and transport needs care.

Shing is one of the most valuable fish in the market. Doctors recommend it as part of the diet for various patients, and a popular saying holds that eating shing builds up the blood quickly. By the original report's estimate, farming by the method described here can produce about 4 tonnes of shing per acre in 10 months, improving the farmer's finances while also saving the fish from extinction.

The report also gives an annual cost and return estimate for mixed culture of shing and magur in a one-hectare pond. The costs are:

• Pond drying or fish-killing chemical: 4,000 taka
• Lime, 250 kg: 2,000 taka
• Organic manure, 2,000 kg: 2,000 taka
• Urea, 250 kg: 2,000 taka
• TSP, 125 kg: 1,875 taka
• MoP, 100 kg: 700 taka
• Supplementary feed, 3,600 kg: 54,000 taka
• 25,000 fry of 4 to 6 cm: 37,000 taka
• Medicines and chemicals: 1,000 taka
• Harvesting and marketing: 4,500 taka
• Miscellaneous: 1,400 taka

The total cost comes to 110,475 taka. Farming a leased pond with a bank loan adds another 28,000 taka. Output is put at 1,800 kilograms of fish, which at 125 taka a kilogram sells for 225,000 taka. The profit is therefore 225,000 minus 110,475, or 114,525 taka.

One thing must be kept in mind when reading these figures. They were drawn up at market prices from an earlier period, and the prices of feed, fry, fertiliser and fish have changed a great deal since. As the report itself says, the figures have to be adjusted to the times; the sensible course is to redo the sums with current local prices. The lasting lesson lies in the proportions: nearly half the total cost goes on feed and more than a third on fry. Cutting feed waste and reducing fry deaths by choosing good seed are the keys to a bigger profit.

Shing farming is now a truly profitable venture. Demand in the local market is huge, and the export potential is good too. With proper planning and care, it can open the door to financial success for a farmer. A sound path for newcomers is to start the first season in a small pond with a moderate number of fry, and to visit the upazila fisheries office for advice and training before starting. The experience of the first year shows how far it is possible to scale up the next.

The ditch beside the house that has lain under water hyacinth for years could, with strong banks, clean water, good fry and quality feed, become a reliable source of family income. The farmers of Dhala have shown the way.

Photo: Shing, the stinging catfish (Heteropneustes fossilis), দিব্য দত্ত (Dibya Dutta) / Wikimedia Commons (CC BY-SA 4.0)