The Asia Pacific Economic Cooperation (APEC) was established in 1989 in response to the growing interdependence of the Asia-Pacific economies. The first section presents the main cultured sea bass species in the Asia-Pacific region. The illustrations of the external and internal anatomy of the fish will guide farmers, especially in the location of organs affected by specific disease agents.
The layout, size, design and construction, and the procedures involved in the preparation of the facility are described in detail. It provides information about the causes and consequences of diseases, how diseases are transmitted, how to recognize early signs of disease and how to prevent further spread of diseases in the facility. The groupers (Family Serranidae) are among the most popular species in the live reef food fishing industry in the Asia-Pacific region.
This manual aims to provide a farmer-friendly practical guide for grouper farmers in Asia-Pacific economies. They have great economic value and are a major part of the live reef fish trade in the tropics.
Other cultured species
External anatomy
Internal anatomy
Where should the farm be located?
Brackishwater ponds
The pond should be able to use the tidal flow for good water exchange and at least 0.8 meters deep.
Floating net cages
Floating net cages should be placed away from the bottom of sea grass or coral reefs to prevent negative effects on them.
What facilities are used in grouper culture?
Allow a minimum of 2 weeks up to three (3) months drying, depending on weather and pond bottom condition. Crack the pond bottom to help eliminate competitors like gobies and to mineralize the soil. Apply lime to the pond bottom and dikes at a rate of 1-2 tonnes/ha of calcium carbonate (CaCO3) or 200-300 kg/ha of calcium oxide (CaO). This is a preventive or remedial process to increase the alkalinity of the ponds and improve the ponds. survival, optimize growth and ensure desirable water parameters and their effective management.
To maintain good water quality, you must monitor the stock closely and keep the pond water at its optimum quality. Frames for the net cages are suspended or attached, the sides of which become walkways for work, feeding and monitoring. The frames must be able to withstand the high salt content of the sea and be resistant to fouling and boring organisms.
Materials for net cages must be strong, weather and pest resistant, non-corrosive and with non-abrasive surfaces. Mooring holds the entire net cluster in a specific location and prevents the cages from being dragged by the water current.
How to collect, handle and transport grouper seed
May to December Peaks usually in June to December or October to November and April to May March to July (April to May peaks) March to August March to August.
Collection gears
The use of light in fish shelters in the Philippines is a matter of convenience for nighttime harvesters and has shown no significant difference in the number and quality of fish collected during the day using the same collection device. Attach sinkers to the bottom and keep the top of the net above water using floats. Here too, with the right treatment, fish can be sorted and other species can be returned to the sea.
Hold the back net to the base with hooks, sinkers and bamboo support along the bottom edge of the front opening. This device may benefit a few people and has been banned in some municipalities in the Philippines. Scissor nets (drag nets, push nets) are used in the Philippines, Sri Lanka and Thailand to collect postlarvae and fry.
The push net (fried dozer, bulldozer) is used in the Philippines, Sri Lanka, Thailand and Vietnam. The problem with this device is the high likelihood of bycatch as it sweeps everything in the water that fits the net size of the aggregator.
Handling and holding facilities
These tanks, wooden tanks, fiberglass tanks and small concrete tanks all have aeration, either a simple portable aerator or a compressor.
Disinfection and conditioning of wild-caught seed
Transport procedures and packing techniques
THINGS TO DO
Transport fish in cool conditions, or if possible, in an air-conditioned vehicle until the shipment reaches its destination. For Cromileptis: separate the packaged fish using newspapers or other opaque barriers between the bags to prevent aggressive behavior during transport. Float unopened bags in the storage facility with seawater for 10 minutes to equalize the water temperature in the bag and aquarium and to acclimate the fish to the new environment.
If the water quality is poor or if the ocean current is strong, do not release fish.
How are groupers cultured?
Nursery phase in hapa nets
Feed to saturation with finely chopped frozen or fresh fish mixed with vitamin-mineral premix at 1-2% (1 kg of waste fish: . 10-20 g vitamin and mineral mixture) 4-6 times a day.
Nursery phase in tanks
If possible, use a flow-through or recirculating water system to maintain or improve water quality.
Grow-out phase in earthen ponds
Salinity 20-32 ppt
Change the water by taking advantage of spring tides or pump water from reservoirs if necessary. If aerators are not available, replace at least 50% of the water or mix the water by hand using paddles.
Grow-out phase in floating net cages
Feed the fish fresh or frozen chopped fish daily at 10% ABW or pelleted food at 3% ABW with half the ration given early in the morning and the other half in the late afternoon. When the fish are about 200 g, reduce the feeding frequency to once a day with fresh or frozen chopped fish at 5% ABW or pellets at 2% ABW. Food should be given in small amounts, enough for the fish to swallow when they come up during feeding.
Ensure adequate water exchange by changing nets clogged with silt and fouling organisms such as algae, oysters, clams and barnacles. If the net needs to be changed due to excessive fouling before sorting, avoid unnecessary handling of the fish by slowly lifting the old net to one side. Net fouling is triggered by rainfall and runoff, which increases the nutrient load on the water.
Floating net cages should be moved to a new location every 2-3 years of cultivation to allow the recently deteriorated conditions to recover. Cultivation duration in the growth phase is 4-7 months depending on the preferred size at harvest.
How to harvest and handle grouper after harvest
Harvesting in earthen ponds
Harvesting in net cages
Packing and transport of live marketable fish
In Australia, a plastic storage bin is used to transport reef fish by air to Hong Kong, China. Restaurants sell live fish by setting up an aquarium or tank with recirculating system, mechanical filters and protein skimmer.
Marketing
How to keep grouper healthy
Monitoring of health status
Causes of disease
Effects of disease
Transmission of disease
Signs of disease
Surveillance and monitoring
When diseases or deaths occur on the farm, samples must be submitted to an accredited laboratory for diagnosis. Correct diagnosis depends on accurate and detailed information on culture conditions and proper preparation of specimens to be submitted to a diagnostic laboratory.
Submitting live samples
PRECAUTION
Sending iced samples
Submitting fixed samples
Cut the fish into several pieces and send only parts that will be useful in the diagnosis.
Common diseases of grouper
Viral diseases
Bacterial diseases
Affected organ fins and tail. bleeding under the skin ② ulcer ③. bulging eye or pop eye with or without bleeding ④. fish die at the bottom of the cage). Organic contamination due to overfeeding and poor water circulation Mechanical injury during transport and handling.
Prevention
Treatment
Fungal diseases
Parasitic diseases
Dinoflagellates are external microscopic protozoan parasites with long, hair-like structures called flagella for movement. Long bath treatment with 0.5 ppm copper sulphate (CuSO4) for 3-5 days with strong aeration; replace treated water and replenish chemicals daily; or. Short bath treatment with 200 ppm formalin for 1 hour with strong aeration. Transfer the treated fish to a clean, parasite-free tank 2 times, 3 days apart.
Add chemical solution to the rearing tank and provide strong aeration After the treatment period, remove or suck out treated water. Ciliates are external microscopic protozoan parasites with short, fine structures called cilia that are used for locomotion. Long bath treatment with 25 ppm formalin (25 ml formalin in 1 ton of water) for 5-7 days, with vigorous aeration; replace treated water and replenish chemicals daily Transfer treated fish to clean, parasite-free tank, 2x every 3 days.
Trichodina has a saucer-shaped body, up to 100 µm in diameter, with cilia around the circumference of the body. Trichodina infection occurs when there are: High levels of organic matter in the water Poor water exchange. Long bath treatment with 25 ppm formalin (25 ml formalin in 1 ton of water), for 1-2 days, with strong aeration.
Long bath treatment with 30 ppm formalin (30 ml formalin in 1 ton of water) for 1-2 days, with strong aeration. Myxosporic infections occur when there is: Poor water quality (fluctuating salinity and low dissolved oxygen). Didymozoid digeneans are very long (up to 80 cm) externally parasitic flatworms that form capsules or cysts on the gills of the host fish.
The copepod Caligus is oval, up to 3 mm in length and 1.6 mm in width, with a pair of suckers on the front edge of the body and four pairs of legs. Short bath treatment with 200 ppm formalin (200 ml formalin in 1 ton of water) for 30-60 minutes, with strong aeration. Manual removal with a wet cloth③ Short bath treatment with 50-100 ppm formalin for 1 hour, with vigorous aeration Transfer treated fish to a clean, parasite-free tank.
Nutritional diseases
Environmental diseases
Management options
Local names of cultured grouper species in the Asia-Pacific
Bibliography
Effects of feeding frequency and amount of feed on the growth of the grouper, Epinephelus malabaricus. Bacteriosis associated with epizootic in the giant sea bass, Lates calcarifer, and the estuarine grouper, Epinephelus tauvina, cage farmed in Malaysia. Intensive pond culture trial with the green grouper Epinephelus malabaricus (Bloch et Schneider) in the Philippines, pp.
Use of artificial hides to increase stocking density and production of estuarine barbel, Epinephelus salmoides Maxwell, reared in floating net cages. A comparative study of Vibrio infections in healthy and diseased finfish reared in floating cages near Penang, Malaysia.
Acknowledgments
Husbandry and Health Management of Grouper
ASIA-PACIFIC ECONOMIC COOPERATION Fisheries Working Group 01/2000
