IMPACT OF GREY MULLET (MUGILL CEPHALUS) DIFFERENT DENSITY CULTURED WITH NILE TILAPIA (OREOCHROMIS NILOTICUS) IN EARTHEN PONDS ON THE WATER QUALITY AND FISH PRODUCTION
Mona Hamed Ahmed
Limnology Department, Central Laboratory for Aquaculture Research, Abbassa, Agriculture Research Center, Ministry of Agriculture, Egypt.
|Received 17/ 10/ 2013||
Accepted 19/ 12/ 2013
This experiment was conducted at a private fish farm from Sahl Eltena , North Sinia, Egypt, to evaluate the effect of stocking density of Grey mullet (Mugil cephalus) in polyculture with Nile tilapia (Oreochromis niloticus) on water quality and growth performance of the two fish species. The study was carried out in nine earthen ponds (5 faddan each with an average depth 1.25m) with three treatments each in three replicates. Each pond was stocked with 10,000 tilapia fingerlings (10.0±0.5g) per feddan. The ponds were divided to three treatments, first, second and third treatments which stocked by 2000, 4000 and 6000 fingerlings (30.0±1.5g) of mullet respectively. The irrigation canal is a branch of El-Salam canal. The results showed that the water quality parameters within the permissible limits for fish culture during the cultural season. Zooplankton and phytoplankton density decreased with increasing fish density. The results indicated that final body weight of Nile tilapia and mullet
increased significantly with the decreasing of stocking density of grey mullet. While, the total production significantly increased with increasing density. It could be concluded that final body weight of M. cephalus increased significantly with the decreasing of stocking density. Net production (kg)/faddan were highly significant in the third treatment.
The results recommended culturing 10,000 fingerlings of Nile tilapia with a density of 6000 fingerlings of mullet to give high economic return.
Key words: Nile tilapia, Mullet, water quality, zooplankton, phytoplankton, density culture.