Gonad Development and Hormonal Induction in Artificial Propagation of Grey Mullet, Mugil Cephalus L

Grey mullet, Mugil cephalus L. is an marine teleost suitable for culture in brackish water. To date, very few report on artificial propagation of grey mullet has ever been recorded and still seed stocking relies on wild recruitment. This paper describe the technique of controlled ovarian maturation and artificial spawning in this fish species. The brood stocks were obtained from cultured matured fish in Gomishan fish farm, Iran. The progressive of gonad development induced by change the season time. The significant changes occur within autumn. Oocyte vitelogenesis and ovulation were induced by hormonal intervention. The use of mammalian gonadotrophins and synthetic analog of luteinizing hormone 2 releasing hormone (LRH-A ) for initiation and advancement and ovarian development is discussed. For successful spawning, a priming injection for females should be when an average egg diameters is 600 ìm or more. A riped ova have a thin layer cytoplasm covering the yolk and have a single oil droplet. In this case, the egg diameter was 960 μm and oil globule 360 μm. Hydration was observed about 10 hrs after the injection of effective dose and spawning within 4–6 hrs after beginning of hydration at 24 ± 1 °C and water salinity 33-35 ppt. During this time GSI increased from 17 to 28 %. The percent of fertilization was up to 80. The 3rd day larvae were fed on a mixture of Chlorella species and Brachionus species and then, newly hatched artemia were added to tanks at the eight day after hatching.