KONINKLIJKE ACADEMIE VOOR OVERZEESE WETENSCHAPPEN ...

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Table 2
Feed and feeding rate for climbing perch larvae
Periods Home-made feed formulations Feeding rates
(% of fish biomass)
Day lst-5th Boiled yolk chicken egg 50-60
Day 6th-15th 50 % fish meal and 50 % soybean meal 30-50
Day 16th-30th 50 % fish meal, 30 % rice bran, 20 % soybean meal 8-10
Day 31st-45th 30 % fish meal and 70 % rice bran 5-7
2.1.2.3. Experiment 3: Intensive Culture of Climbing Perch in Earthen Ponds
— Experimental Design
The treatment of intensive culture system was carried out in Phu Loi village,
Chau Thanh district, Can Tho province. The culture system includes two earthen
ponds with a total area of 3,770 m2, including fish pond 1 (270 m2) and fish
pond 2 (3,500 m2) at two stocking densities of 30 and 50 fish/m2 (treatment I:
30 fish/m2, treatment II: 50 fish/m2). During a culture period of six months, the
fish were fed with mainly home-made feed (by-products of processing factory or
agriculture) at a rate of 3-8 % fish biomass/day, and adjusted following the
growth rate of fish.
— Data Collection
Water quality parameters such as water temperature (°C), water transparency
(cm), water pH were measured at 7:30 a.m. and 14:00 p.m. The other parameters
such as dissolved oxygen, NNR,\ P-PCV, COD, H2S and natural food resources
(phytoplankton, zooplankton and zoobenthods) were measured monthly.
Number of spawned fish, fecundity (number of eggs per kg of female), fertilization
rate (%), hatching rate (%), and survival rate of larvae (%) after three free
swimming days, daily weight gain (g/day) and special growth rate (%/day) were
also recorded every fifteen days for nursing (ten fish) and every month for growing
out (thirty fish).
— Water Quality Management
Water samples were collected monthly at the same time as fish samples in
ponds and analysed following the methods used by the Central Laboratory,
College of Aquaculture and Fisheries Sciences, Can Tho University:
— Water temperature (°C): by using temperature metre (HANNA);
— Transparency: by using Secchi disc;
— DO (mg/1): by using Winkler method (DO metre);
— Water pH: by using pH metre and pH paper;
— N-NH,': by using Indophenole method;
— P-P043 : by using Molibden blue method;