Milkfish Production and Processing ... - WorldFish Center

Antonio Villaluz
Antonio Villaluz
g) Collect the rotifers in a 40-50 micron
filter bag installed at the end of the
hose. The harvested rotifers can be
used as feed for the larvae or as starter
for other tanks.
8. MILKFISH TANK HATCHERY
PRODUCTION METHOD
(INTENSIVE OR INDOOR
SYSTEM)
8.1 Description
Generally tank size used in intensive larval
rearing is from 5- 0 m and depth is from
1-1. m (Figures 6 and 7). Larval tanks are
either made of concrete or canvas. Shade
is also provided to prevent strong sunlight
and rain from entering the larval rearing
tank. The average yield is 10 fry per liter of
rearing water.
Figure 6. Rectangular larval rearing tank.
Figure 7. Circular larval rearing tank.
The problems of low quality fry and deformities
in intensive hatchery system have been
addressed by providing adequate nutrition and
vitamins and good water quality. The advantage
of intensive system is that more fry can be
produced in a limited area. Production schedule
can be maintained even in unpredictable climatic
conditions because environmental parameters
Milkfish Production and Processing Technologies in the Philippines
in intensive tank being smaller are relatively
easier to manipulate.
8.2 Larval Rearing Procedure
a) Stock milkfish larvae (Day 0) in
concrete tanks (10 ton rectangular
tank for intensive culture and 0 ton
circular tank for semi-intensive) at a
density of 0/l.
b) Maintain temperature at 5.6- 1ºC,
salinity at - 5 ppt and DO at
5.5 ppm.
c) Prepare enriched rotifers and Artemia
by feeding them with HUFA booster
diets supplemented with Vitamin C
or microalgae with high HUFA content.
Supplementation of rotifers with commercial
larval feed (MBD, Norsan R-1)
may be done to improve growth and
survival of larvae.
d) On day and thereafter, feed with
rotifers supplied with Chlorella
(Nannochloropsis sp.) Maintain a
density of 7-8 rotifers/ml.
e) Starting day 7, feed with practical
diet (particle size < 50 µm) at a rate
of 8 g/ton rearing water/day. Feed
four times a day at 09:00am, 11:00am,
1:00pm and :00pm. Increase the
amount to 1 g/ton/day on Day 15
until harvest.
f) After two weeks, feed with Artemia
nauplii at 0.5-1.0/ml.
g) Chlorella, Tetraselmis or Isochrysis
are added to condition the water and
serve as feed for rotifers.
h) Harvest after 1- days after hatching.
Survival rate is 0%.
i) The protocol for milkfish tank hatchery
operation is shown in Figure 8.
9. MILKFISH POND BASED
HATCHERY PRODUCTION
METHOD
9.1 Description
The optimum size for pond based hatchery
production method or semi-intensive larval
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