تأثيرات معدلات التغذية على نمو يرقات البلطيOreochromis spilurus في مياه من البحر الأحمر

Abstract EN

Oreochromis spilurus fry (91g.

average weight) were transferred from fresh to water from the Red Sea (approximate 42 ppt).

The fry were randomly divided into 6 groups.

Each group was distributed among 4 tanks of size 40L of water each (40 fry, per tank).Fry were fed for 50 days on 6 different feeding rates, (4 %, 6 %, 8 %, 10 %, 15 %, and 20 %).

i.e.

(F4, F6, F8, F10, F15, and F20), respectively.

F20 gained the highest weight increment rate, followed by F15 with no significant difference between the feeding regimes.

The F4 gained the lowest (P < 0.05) weight.

The best FCR (1.12) resulted from F6 followed by F4, F8, and F10, and the lowest (2.42), was obtained from F20 followed by F15 (1.17).

PER values of F4, F6, F10, and F20 were significantly difference while values of F6, F8, F10, and F15, were not.

Highest PER (2.34) recorded by F6 and the lowest (1.33) was recorded by F20.

Feed wastage of 40 %, and 52 % were observed at the end of the experiment with F15, and F20, respectively.

Studied fry performed high survival rates ranging between 94.2 % and 99.7 % except, for the F20 that recorded 71.9 % survival rate.

It could be concluded from the study that, suggested optimal feeding rate for O.

spilurus fry of (91mg.

average weight) in high saline water (42 ppt.) ranged between 8 %, and 10 % of their body weight per day.