Journal of Fisheries and Aquatic Science1816-49271996-0751Academic Journals Inc.10.3923/jfas.2006.87.96Mugil cephalus on Natural Food and Phytoplankton Selectivity at Different Feeding Regimes in Earthen Fishponds]]>MarakbyH.I. El-EidA.M. AbdelghanyA.E. -TawwabM. Abdel 1200611This study was carried out to investigate the ability of striped mullet (Mugil cephalus) to select phytoplankton at different feeding regimes. Striped mullet (35.1±1 g) was stocked at a rate of 1 fish/m2 for 14 weeks. The first treatment (control) received only organic and inorganic fertilizers. The second treatment (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 (T2) received only supplemental feed at a rate of 5% of fish bw. Each treatment was represented by three replicates. The maximum final weight was obtained at T1 and T2 without significant differences, while the minimum one was obtained at control treatment. The fresh weight of stomach content in control treatment was the highest one. Phytoplankton occurrence in gut content of striped mullet was higher in control sharing 70-80% of total gut content, while it was significantly lower in T2 (p<0.05). Detritus consisted mainly of scraps of macrophytes, organic particles including feed particles and mud. The composition percentage of detritus in fish stomach was significantly differed and ranked as T2>T1>control. Zooplankton sharing to gut content was generally small in T2 and the highest content was obtained at control. Whenever zooplankton occurred, it was not exceed 10.0% of the total components in fish stomach, and it consisted of parts of animals especially cladocera, copepoda and rotifers. Sometimes, parts of insects and zoobenthos were found. The main phytoplankton genera found in fish stomach are belonged to Cyanobacteria, Chlorophyceae, Bacillariophyceae and Euglenophyceae. Bacillariophyceae represented the main phytoplankton division, while Cyanobacteria followed by Chlorophyceae were the less abundant divisions at all treatments. Euglenophyceae represented moderate abundance in fish stomach content. Striped mullet selected Bacillariophyceae and Euglenophyceae at all treatments, meanwhile Cyanobacteria was sometimes selected at T1 and T2. Chlorophyceae was not selected at all and it was gut entered with water and mechanically swallowed together with other foodstuffs. This result indicates that striped mullet naturally does not consume food at random but have the ability to select and choose the preferred foodstuff and could use supplemental feed efficiently.]]>Abdelghany, A.E.,19931993pp: 447-453pp: 447-453Abdelghany, A.E. and M.H. Ahmad,200233415423Abdel-Tawwab, M., A.E. Abdelghany, Y.M. El-Ayouty and A.A. El-Essawy,2002Oreochromis niloticus L.) in earthen ponds.]]>8018911907Ahmad, M.H., A.E. Abdelghany and M. Abdel-Tawwab,2001417998Boyd, C.E.,1984Brusle, J.,19811981pp: 185-217pp: 185-217Dytham, C.,1999pp: 147pp: 147Green, B.W.,1992101213222Ibrahim, A.M., N.F. Abd El-Hakim, Z.A. Nagdy and N.A. Ali,20037107133Ivlev, V.S.,1961pp: 322pp: 322Jana, S.N., S.K. Garg and B.C. Patra,2004Mugil cephalus (Linn.), in inland saline groundwater ponds.]]>20110117Katz, T., B. Herut, A. Genin and D.L. Angel,2002234205214Larson, E.T. and A.L. Shanks,19961301928Lupatsch, I., T. Katz and D.L. Angel,20033413671377NRC.,1993Pages: 114Pages: 114Odum, W.E.,1970Mugil cephalus.]]>1970pp: 222-240pp: 222-240Oren, O.H.,1981pp: 507pp: 507Porter, C.B., P. Krost, H. Gordin and D.L. Angel,1996Mugil cephalus) as a forager of organically enriched sediments below marine fish farms.]]>484755Prescott, G.W.,1961pp: 990pp: 990Sarig, S.,19811981pp: 391-409pp: 391-409Turker, H., A.G. Eversole and D.E. Burne,2003Oreochromis niloticus (L.), size on phytoplankton filtration rate.]]>3410871091Wells, R.D.,1984Mugil cephalus L. in lake Waahi and the Waikato River at Huntly, New Zealand.]]>181319Harrison, I.J. H. and Senou,19971997pp: 41-42pp: 41-42