FOOD AND FEEDING HABITS OF OREOCHROMIS NILOTICUS UNDER THE EFFECT OF INORGANIC FERTILIZER WITH DIFFERENT N:P:K RATIOS IN ABBASA FISHPONDS

ABDEL-TAWWAB, MOHSEN

doi:10.21608/ejar.2000.321714

FOOD AND FEEDING HABITS OF OREOCHROMIS NILOTICUS UNDER THE EFFECT OF INORGANIC FERTILIZER WITH DIFFERENT N:P:K RATIOS IN ABBASA FISHPONDS

Document Type : Original Article

Author

MOHSEN ABDEL-TAWWAB

Central Laboratory for Aquaculture, Agricultural Research Centre, Giza, Egypt

10.21608/ejar.2000.321714

Abstract

The food and feeding habits of Nile tilapia (Oreochromis niloticus) in ponds received inorganic fertilizer with different ratios of N:P:K were studied. The ratios were 20:20:5,20:40:5, and 20:20:0 and applied at a rate of 40 kg/feddan/month. It was found that, 0.mloticus mainly consumed phytoplankton. The main items found in fish stomach belonged to Cyanophyta, Chlorophyta, Bacillanophyta and Euglenophyta. Detritus consisted mainly of scraps of macrophytes and mud. Zooplankton was occasionally found. The most frequently species represented in the food were Anabaena spp., Mensmopedia eleganse, Microcystas aeruginosa, Oscillatona spp. and Spruhna sp. (Cyanophyta). Ch/Dregs spp., Pandonha morum, Pediastrum spp. Scenedesmus spp. and Shereoderia setigera (Chlorphyta), Amphora ovahs, Gyrostgma attenuatum, Melosira granulate, Navicula map., Nitzschia spp., Pin/J/aria spp. and Synedra sp. (Bacillanophyta) and Euglena spp. and Phacus spp. (Euglenophyta). 0.nthaticus could select only Cyanophyta and Euglenophyta dunng the investigation period and sometimes select Bacillanophyta.