Seabass is an economically important food fish in the tropical and sub-tropical regions of Asia and the Pacific. It is a highly carnivorous fish but can be trained to feed on formulated diets. It can tolerate a wide range of salinity from freshwater to full seawater. However, lower salinity (10-20 ppt) promotes better growth.
Scientific name : Lates calcarifer
Common English names : Giant perch, white seabass, silver seaperch, palmer, barramundi
Local names : Kakap, apahap, bulgan, salongsong, katuyot, matang pusa
Newly-hatched seabass eggs can be raised in the hatchery until metamorphosis, or until the larvae are 15-21 days old or 1.0-1.5 cm total length.
Tanks of 3-25 tons in capacity will be needed, to which 30 larvae per liter will be stocked. The larvae can be fed a combination of natural food (rotifers, then with newly-hatched Artemia nauplii) and formulated diet. Survival rate can range from 50-70%.
Phase 1. Seabass fry (15-21 days old) can be reared in earthen ponds, land-based tanks, or in net cages (hapa) set in ponds. Ponds are preferably not more than 2,000 m2 for easy management.
Ponds are prepared and fertilized at least one week before stocking to eradicate predators and grow zooplankton. This phase can take 10-20 days. Fish are harvested when size is 2.5 cm total length.
Concrete nursery tanks are 3-5 tons where fry can be weaned to formulated diet. They are fed every 2 hours, size-graded every 5-7 days, and harvested or transferred at 2.5-3.0 cm total length. This can take 30 days.
Net cages (hapa) set in ponds can measure 2 x 1 x 1 m. Optimum stocking density is 150-200 fry/m3. Fry are fed with natural zooplankton, mysids, mosquito larvae and/or formulated diet, graded every 5-7 days, and harvested or transferred to B-net when the fry attains 2.5-3.0 cm total length. This can take 30 days.
Lights can be provided to attract zooplankton and encourage fish foraging during the night.
Phase 2. At this stage, fish juveniles are fed trash fish or formulated diet 6x per day until they reach 20-50 g, the ideal size for grow-out culture. Phase 2 nursery can be done in concrete tanks or cages in ponds.
In concrete tanks (3-5 tons), juveniles are fed with formulated diet every 2 hours. Juveniles are graded and the tanks cleaned every 5-7 days.
In ponds, B-net cages can measure 2 x 3 x 1 m or 1 x 3 x 1 m. The same procedure is used as in the above and the fish are harvested at 7-10 cm total length.
Seabass juveniles are stocked at about 20-50 g average body weight. They are fed fish by-catch at 5-10% biomass or formulated diet at 3-5% biomass given 2-3x per day. Seabass can reach marketable size of 300-600 g in about 4-7 months. Grow-out culture can be done in ponds or cages.
Pond culture. The recommended stocking density is 5,000 pcs/ha. Water is changed at 40-60% of volume daily during spring tide.
Cage culture. Cage size is 5 x 5 x 3 m with a recommended stocking density of 15-20 pcs/m3.
For further information contact:
Technology Verification and Extension Section
SEAFDEC Aquaculture Department
Tigbauan 5021, Iloilo
Tel: (033) 336 2937, 336 2965, 335 1009
Fax: (033) 335 1008, 336 2891
E-Mail: [email protected]
Room 102, Ground Floor
Philippine Social Science Center
Commonwealth Ave. corner Central Ave.
1101 Diliman, Quezon City
Mobile Nos. +63918-919-6904, +63918-910-9443