The Biology and Culture of Tilapias

Table 8. Semi-intensive cage culture of tilapias using mixed feeds. Bracketed entries are representative of the range of fish sizes used.

Stocking data Growth data Harvesting data
Feed composition Pmi Bi G MSG DRIB Pmf Bf MP
Suecies and location and feeding rate (g) N/m3 (kg/m3) (g/d) (5%) (%) (g) (kglm3) (kglm3) FCR

Culture

period

(m0) References and remark*

1. S. niloticus, rice bran in the (10) (100) (1.0) (0.8) - -^150 15 2.3 -
   Laguna de Bay presence of algal
   (Philippines) blooms


2. S. mossambicus, Rice bran. 70%; 10 50 0.50 0.52 157 1.9 57.1 2.8 0.77 6
   Laguna de Bay chopped snails, 30%;
   (Philippines) equivalent to 41%
   protein ;in the pre-
   sence of algal blooms

6 Anon. 1979a: Floating cages;

20 x 25 x 2.5 m deep;

1.000 m3 capacity

3 Pantastico and Baldia 1979;

6 cages (5.4 mm mesh)

25 x 25 x 1.5 m deep; each

with 9.4 m3 capacity

3. S. aureus. Undefined
   Lake Ilopango
   (San Salvador)


4. T. rendalli, Alocasia leaves 22.5 100 2.25 1.3 173 1.5 200to 21.6 3.87 -
   Ponds (Colombia) + 0.5 to 1.0 kg 250
   wheat bran daily


5. S. esculentus, Brewery waste, 99%; 19 18.9 0.36 0.16 25 0.4 46.6 0.70 0.06 -
   Lake Victoria fish meal. 1%; DFR =
   (Tanzania) 15 to 30% B


6. T. zillii, as 5. above plus 2.56 84.2 0.21 0.14 164 1.6 15.6 0.92 0.23 -
   'Lake Victoria plant leaves
   (Tanzania)


7. S. esculentus + as 6. above 16.3 22.9 0.37 0.45 83 1.1 (80) 1.78 0.30 -
   T. zillii, Lake
   Victoria (Tanzania)


8. S. mossambicus? Rice bran. 16/21; 1.5 - - - - 80to - - -
   Negombo Lagoon coconut oil cake. to 250
   inlet (Sri Lanka) 4/21 ; cattle blood, 3.0
   1/21 ;plus wheat
   flour. 450 g/21 kg;

Pmi :

N:

Bi :

G:

MSG :

DRIB :

Pmf :

Bf :

MP :

FCR :

mean weight at stocking

number of fish

mean biomass at stocking

average growth rate of individual fish during the culture period

average monthly spcific growth rate

daily rate of increase of the biomass calculated from Bf = Bi (1 + i)" where n is the culture period in days and i is EB

mean weight at harvest 100

mean biomass at harvest

average monthly production: (Bf - Bi) observed and recalculated on a 30-day basis

feed conversion ratio, on a net weight basis unless otherwise indicated

Street 1978; 7 commercial

cages; each with 30 m3

capacity

5 McLarney 1978:^1 m3 cages;

survival 96%

< 6 Ibrahim et al. 1975; cage,

42 m3; (8 mm mesh)

3 as 5. above

4.7 Ibrahii et al. 1975: cage,

125 m3 (20 mm mesh)

6 Sollows pers. comm.: floating

cages