What are the culture methods for Thai marble goby?

The marble goby commands a high market price and has good prospects, and many people want to farm it but do not know how. The author has written this article especially for the reference of farmers; each culture method suits farmers in different regions and environmental conditions.

1. Pond culture

The pond for culturing Thai marble goby should preferably be 3 mu in area, usually no more than 8 mu, with a water depth of 1.5 m, little silt and a good water source. Stock 3000-3500 fry per mu. For first-time culture of Thai marble goby, it is advisable to choose the single-batch grow-out method.

Before stocking the fry, the pond must be cleared and disinfected to remove trash fish. Artificial spawning nests must be placed on the pond bottom: plastic pipes 11 cm in diameter and 35 cm long can be used, with two 2 m wooden strips tying 9 plastic pipes into a row, about 80 rows per mu depending on stocking density. The artificial nest pipes must be 20 cm off the pond bottom, fixed with stakes and slightly tilted, to prevent soil and fish from accumulating inside the pipes. Artificial spawning nests are an important measure for effectively expanding the ecological culture area, increasing stocking density and raising yields.

When the pond water temperature is above 22°C and it is easy to cultivate biological bait, the fry can be released. With the pond water depth at 1 m, use plastic sheeting to partition off 1/3 of the water surface; according to the fertility of the pond bottom, apply 250-500 kg of fermented manure or mechanically processed organic fertilizer to this 1/3 of the water surface, and at the same time disinfect the water with 5 g/cubic m of strong chlorine; after 5-7 days, once large numbers of water fleas and other plankton have been cultured, the fry can be stocked. If biological bait is abundant throughout the pond and there are rich resources of freshwater shrimp, the partitioning method need not be used. When stocking, the temperature difference between the fry bag and the pond water should not exceed 2°C.

Because of the special nature of the scales on the body surface of Thai marble goby fry, fry over 3 cm in size are easily injured during transport, and improper disinfection before stocking will reduce the survival rate. Therefore, it is advisable to buy disinfected, packaged fry of 2-2.5 cm that can be stocked directly. The fry are concentrated in this 1/3 of the water surface for the first stage of rearing. With sufficient bait, the fry can grow to 3 cm in 1 week and reach 4-5 cm in 1 month; at this point the plastic sheeting dividing the pond can be removed, letting the fingerlings enter the larger pond for the second stage of rearing.

Before this, stock and cultivate live bait in the other 2/3 of the pond surface. The live bait is best small-sized, highly reproductive fish species such as topminnows, no fewer than 10,000 per mu; when the fingerlings enter the second stage of rearing, also stock freshwater shrimp fry that can reproduce naturally under freshwater conditions, no fewer than 500,000 per mu, or stock desalinated giant river prawn fry in batches, and feed shrimp feed at fixed times and in fixed amounts according to the @#@234@#@ standard. The fry prey on the shrimp fry, fish fry, small shrimp and small fish in the pond, and the survival rate of grow-out is generally above 80%. After 3-4 months they can grow to 10-12 cm and 20-30 g in body weight and move into adult fish culture. During adult fish culture, 50-100 silver carp can be polycultured per mu, which helps control water quality.

When the amount of live small fish and shrimp in the culture water is insufficient, Thai marble goby switches to feeding on artificial feed, so chilled fresh fish chunks or artificial compound feed or artificial compound powdered feed with a protein content of no less than 38% must be supplied in good time. Feeding stations should be set up when feeding: 6-8 hanging baskets per mu, about 20 cm from the pond bottom, to suit the Thai marble goby's dislike of swimming. Place the processed block feed or chilled fresh fish chunks in the hanging baskets, and increase or decrease the feed amount as appropriate according to feeding conditions; leftover bait can be poured into the pond to feed the small fish and shrimp. Feed conversion ratio: 6-8 when feeding small trash fish, 2-2.5 when feeding artificial compound feed; after 6-7 months of culture they reach market size.

Polyculturing small fish and shrimp with Thai marble goby forms a good food chain. The small fish and shrimp are not only the best bait for Thai marble goby, but also effectively clean up leftover bait and help keep water quality stable.

2. Pond cage culture

When Thai marble goby enters the grow-out period, using ground cages to catch large-size fingerlings and transferring them by size into cages set up in the same pond is a culture method that solves the size variation of single-batch grow-out and allows batch harvesting for market. The stocking density is 10-20 fish per sq m; fish whose body surface is injured during capture should be treated according to the treatment methods for body surface diseases.

Ponds used for cage culture are usually 6-8 mu in area with a water depth above 1.5 m. In hot seasons, the water at a depth of 1 m should not exceed 32°C; duckweed and water hyacinth can be grown on the water surface to lower the water temperature, and flow-through methods or paddle-wheel aerators can be used to aerate at regular intervals and improve water quality.

The cage material is made of knotless netting. For fingerlings of 30-50 g each, use knotless mesh of 1.5 cm; for fingerlings of 100 g each, use knotless mesh of 2.5 cm. Cage specifications can be chosen according to conditions as 3 m x 4 m or 4 m x 6 m; the cage uses buoyant material so that the cage mouth stands 20 cm above the water surface and the bottom is 20 cm off the pond bottom.

According to the size of the cage, place 3-4 rows of artificial spawning nests and set up 1-2 hanging baskets as feeding stations.

3. Cage culture in large water bodies

When the natural water temperature is above 24°C, cage culture can be used in reservoirs, lakes and slow-flowing rivers with abundant water resources; this is a good method with low investment, high yield and high efficiency.

Choose a culture site suitable for setting up cages: the water quality must be good, with no industrial pollution, a slow flow rate, a water depth of no less than 2 m, few motorboats nearby, and convenient transport.

There are many cage specifications, but the most commonly used is 4 m x 6 m x 2.5 m. Cage materials can be knotless netting, bamboo strips or galvanized embossed iron mesh; the mesh size depends on the size of the stocked fry, as long as they cannot escape or get stuck. Use buoyant materials (foam, floating drums) so that the upper part of the cage stands 40-50 cm above the water surface; the top can be covered flat with wooden boards to prevent sun exposure, with two movable feeding windows of 40 cm x 50 cm cut in the top. Usually several cages are linked together and set in reservoirs or lakes, with people living on top for convenient feeding and management. Cage culture must stock healthy large-size fry; when purchasing large-size fry from other farms, inspect on site and select carefully, and after disinfection and temporary holding, wait until injuries caused by transport have healed before putting them into the cages for culture.

Stocking density. Stock fingerlings of 50-80 g each or above at a density of 30-50 fish per sq m. Stock in the morning or evening at @#@233@#@, with the same size in the same cage; use a bucket to put the fingerlings into the cage with water and let them swim away on their own. Never pour the fish into the cage. Feeding should begin on the third day after stocking, placing the feed into the feeding frame and sinking it 30 cm from the cage bottom. Feed twice a day, increasing or decreasing the feed amount according to actual feeding conditions. The surroundings of the cage must be cleaned frequently to remove algae and keep the water flowing, and a water pump should be used to suck out debris from the cage bottom. After 6-7 months of culture they reach market size.

4. Cement pond culture

Using soft-shelled turtle culture facilities with insulation conditions to culture Thai marble goby not only lets the greenhouses of the turtle industry generate returns again, but is also a good way to gradually realize industrialized culture of Thai marble goby; it is suitable for culture in regions with low winter and spring temperatures. In the middle and lower reaches of the Yangtze River, when the water temperature reaches 22°C in May each year, freshwater shrimp reproduce in large numbers; using ponds to culture marble goby, from September-October they are harvested and transferred to greenhouses for grow-out, and can reach market size the following year.

No artificial spawning nests are set in the pond; use micro-circulating water or timed aeration for oxygenation, and remove waste regularly to prevent water quality deterioration. Use feeding stations to feed bait, feeding every afternoon, and inspect and clean the feeding stations the next day.

The grow-out pond area should be no less than 30 sq m. The stocking density for large-size fry of 30-50 g each or above is 8-15 fish per sq m. After mastering the technical characteristics of culturing this fish, the stocking density can gradually reach high-density industrialized production of 30-50 fish per sq m.

5. Shrimp and fish polyculture

Polyculturing Thai marble goby in shrimp ponds has low investment and good returns. The shrimp pond should have little silt, with shrimp as the main culture species while also rearing Thai marble goby fry to size. Because Thai marble goby has good salt tolerance, in whiteleg shrimp or giant river prawn culture ponds, 10-15 days after the shrimp fry are stocked, when the salinity is 2‰-5‰, the fish fry can be stocked directly, at 100-200 Thai marble goby fry per mu; their main food is small, slow-growing shrimp fry. When harvesting shrimp, any Thai marble goby caught must be disinfected promptly; because Thai marble goby has the habit of burrowing into mud and staying still, careful capture is needed after the pond is drained. Fry cultured for 3 months usually reach 9-10 cm and can be transferred to pond cage culture.

6. Fish and fish polyculture

In culture ponds mainly raising monosex tilapia or pufferfish, under artificial feed feeding conditions there are usually many freshwater shrimp, which are the best bait for Thai marble goby. 50-80 Thai marble goby fry can be stocked per mu at the same time, and with a small number of artificial spawning nests placed, an additional 20-30 kg of Thai marble goby can be harvested per mu.