Turkish Journal of Fisheries and Aquatic Sciences
2005, Vol 5, Num, 1 (Pages: 1-10)
The Assessment of Water Quality and Primary Productivity in Earthen Fishponds Stocked with Stripped Mullet (Mugil cephalus) and Subjected to Different Feeding Regimes
2 Department of Animal Production, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt
3 Fish Nutrition Department, Central Laboratory for Aquaculture Research, Abbassa, Abo-Hammad, Sharqia, Egypt Viewed : 4712 - Downloaded : 3885 The effects of different feeding regimes of striped mullet (Mugil cephalus) on water quality and phytoplankton fluctuations in earthen fishponds were studied. Striped mullet (35.1±1 g) was stocked at a rate of 1 fish/m2 for 105 days. The first treatment ponds (control) received only organic and inorganic fertilizers. The second treatment ponds (T1) received organic and inorganic fertilizers as in the first treatment and supplemental feed at a rate of 3% of fish body weight (bw). The third treatment ponds (T2) received only supplemental feed at a rate of 5% of bw. Each treatment was represented by three replicates. Results revealed that there were no significant differences in water temperature, pH, free ammonia, and water conductivity among the treatments. Dissolved oxygen, orthophosphate and nitrate concentrations in control and T1 ponds were significantly higher than those of T2 ponds. Water turbidity was significantly higher in T1 ponds than that of the other treatment ponds. Phytoplankton and zooplankton abundances were significantly higher in control and T1 ponds than those of T2 ponds. The final weight of striped mullet was maximized at T2 ponds, while the lowest one was in control ponds. It could be concluded that striped mullet could utilize both supplemental and/or natural food. Keywords : Water quality, phytoplankton, zooplankton, supplemental feed, striped mullet, growth