ON 'rilE GROW'l'1I OF OREOCHROMIS AUREUS (STIUN _) IN I.J\KF. Ml\N7.AIJ\II, EGypor

ON ‘rilE GROW’l’1I OF OREOCHROMIS AUREUS (STIUN _) IN I.J\KF.
Ml\N7.AIJ\II, EGypor.
T.E. J\lIDEL-Bl\KY and 5.5. EL-SERJ\FY.
Zool. llep. Fae. seL, Demietta, Mans. University.
Zool. Dap. Fae. Sci., Danha, Zaga. university.
ABSTRACT
Growth rate of o. aureus at three different ecological
zones, EI-Gamll, El-Ginkah and Middle of Lake Manzalah has
been studied. The rate of growth at the early years of
life was higher at EI-Gamil and El-Glnkah zones than that at
the Middle zone. The growth of older fish In the Middle
zone has proceeded the other two zones. Tha Rosa Lee
phenomenon was clearly observed at El-Gamll and El-Glnkah
zones, while it was rather reversed in the Middle zone. The
growth of O. BUreu& at Lake Manzalah was best described ey von Bertalanffy exponential growth equation. The derived
equations were as follow: