Two hundred and four Oreochromis niloticus brood stock were used in the experiment. Males and females were
classified into three groups according to their body weights as follows; large (400 – 650 g), medium (160 – 300 g) and small
(80-120 g) which coded A, B and C; respectively. All possible nine combinations between the three weight categories were
conducted. Testes and ovary weights were significantly affected (P < 0.001 & P < 0.01 respectively) with different
broodstock size groups. The highest testes and ovary weights were recorded at large-sized group, while it decreased
steadily from medium to small-sized groups; respectively. Absolute fecundity, relative fecundity, and egg weight were
all significantly affected (P < 0.01) with female size. The highest absolute fecundity and egg weight were obtained in
large-sized females while the highest relative fecundity was obtained in the small-sized females. Gonado-somatic index
didn't affect significantly with the various sizes of the female. Total collected fry number and growth performance
represented as fry weight, length, and condition factor at the age of 6 weeks were all significantly (P < 0.001) affected
with broodstock size combinations. The highest fry numbers were obtained from the AB, AC, and BC combinations
respectively, whilst the lowest were recorded by BA and CB combinations. The highest fry weight and length at the age
of 6 weeks after hatching were obtained from combinations AA, BB, and CA respectively. Nonetheless, the AC
combination showed the lowest body weight and length. The highest condition factor was recorded by AB combination
while the lowest was for the AC's.