The effect of mature broodstock origin on the spawningefficiency of grey mullet, Mugil cephalus

IntroductionUnderstanding the biochemical composition of good batches of mullet eggs is abeginning of an investigative process that may one day make it easier to distinguishgood eggs from undesirable ones.Aim of the studyThe present study was conducted to investigate the variations, if any, in thereproductive biology and biochemical composition of wild-caught and pond-rearedbroodstock of Mugil cephalus.Materials and methodsImportant biochemical constituents (protein, lipids, amino acids and fatty acids) ingonads and freshly spawned eggs of both wild and cultured female broodstock ofM. cephalus were analysed.ResultsThe results showed that the ovarian activity of cultured prespawning females waslower than that of wild females. The activation and fertilization rates of spawned eggsvaried between wild and cultivated mullet females. In addition, there was malformationduring the embryonic development of fertilized eggs obtained from cultivated females.There was a significant difference in biochemical contents – namely, amino acids andfatty acids – in gonads and spawned eggs between the two stocks, which seems tobe due to differences in habitat conditions, mainly salinity and ion concentrations.ConclusionWith such information, we may be able to enhance the survival of mullet eggs throughproper control of husbandry practices including environmental parameters, nutritionand methods for spawning.