Studies ON PRODUCTION AND SPAWNING OF OREOCHROMIS SP.

Abstract

This study was carried out at three private fish farms in Edko and Kafr El-Dawar (El-Bohira Governorate) and Borg El-Arab, Alexandria governorate, Egypt. Finally, Faculty of Agriculture (Saba Basha) Alexandria University experimental fish farm at Abbis district of the city of Alexandria, Alexandria governorate, Egypt. It was conducted to evaluate and determine The correlation between soil type, and quality on total Nile Tilapia Oreochromis niloticus yields and net income with or without adding fertilization (organic and inorganic fertilizers) along with applying two different culture systems (monoculture and polyculture). Second, effect of filter feeding fish reared around Nile Tilapia cages on soil and water quality underneath the rearing cages and its effect on growth performance• of Nile Tilapia. Third, observe the optimum feeding level on the growth performance of Nile Tilapia broodstocks and the quality of produced fry. Finally, effect of different dietary protein levels introduced to Nile Tilapia broodstocks at pre­ spawning period on the resistance of produced fry to winter season reared in broodstock ponds with and without fertilization.