@article { author = {mansour, enas}, title = {Environmental impacts on Chemical Characteristic in Sediment of Lake Mariout - Egypt}, journal = {Egyptian Journal for Aquaculture}, volume = {10}, number = {2}, pages = {1-17}, year = {2020}, publisher = {Blue Resources for Aquaculture, Environment and Society Development}, issn = {2090-7877}, eissn = {2636-3984}, doi = {10.21608/eja.2020.28915.1020}, abstract = {The Mariout Lake is considered an important natural resource for fish production in Alexandria Governorate, it has been subjected to various types of pollution, the lake acts as a receptor for domestic wastewater and industrial wastes. So this study was conducted to determine the effect of environmental impacts and pollution on chemical properties of different cores of Mariout lake sediment, Surficial (0-10cm) and sub-surficial (10-20cm) sediments were collected seasonally using vertical soilsampler from seven sites during winter, spring, summer, and autumn 2017. The study showed that the mean values of organic matter, organic carbon and total carbon, total nitrogen and total phosphorus were significantly increased (P}, keywords = {Mariout lake,chemical properties,pollution,seasons}, url = {https://eja.journals.ekb.eg/article_90670.html}, eprint = {https://eja.journals.ekb.eg/article_90670_4851069bec9c92b866191bb0603c9473.pdf} } @article { author = {Elabd, Hiam and abd el-latif, ashraf and Shaheen, Adel and matter, Aya}, title = {Identification of emerging Acinetobacter johnsonii virulence and antibiotic resistance genes associated with high mortality in cultured Oreochromis niloticus}, journal = {Egyptian Journal for Aquaculture}, volume = {10}, number = {2}, pages = {19-33}, year = {2020}, publisher = {Blue Resources for Aquaculture, Environment and Society Development}, issn = {2090-7877}, eissn = {2636-3984}, doi = {10.21608/eja.2020.29010.1021}, abstract = {The present study was planned to investigate the causative agent of Oreochromis niloticus summer mortality that resulted in significant economic losses in Port Said Governorate, Egypt during 2017.Many bacterial isolates were identified, among which Acinetobacter johnsonii has been selected to be the focus of the current study. Acinetobacter johnsonii_Egy was isolated and identified using the analytical profile index (API) 20 E, sequencing 16S ribossomal RNA gene fragment and phylogenetic analysis. A drug resistance evaluation revealed that A. johnsonii was resistant to ampicillin, gentamicin, lincomycin, nalidixic acid, tetracycline, and oxytetracycline among the tested antibiotics. Experimental infection was performed and challenged fish revealed similar clinical signs as seen in naturally infected ones. The disease appears to be highly infectious and lethal, causing 100% cumulative mortality during experimental infections. Virulence genes (fimH, traT, and iutA) and antibiotic resistance genes (qacED1, qnrS, sul1, dfrA, and aadA1) presence was confirmed in the A. johnsonii_Egy isolate. In conclusion, A. johnsonii is highly infectious to O. niloticus and might have a great influence on transfer of the antibiotic resistance in aquaculture. According to the available knowledge, this study is first to report A. johnsonii as emerging opportunistic pathogen in the Egyptian Nile tilapia (in Port Said).}, keywords = {Acinetobacter johnsonii_Egy,O. niloticus,Antibiotic Susceptibility,Virulence}, url = {https://eja.journals.ekb.eg/article_92446.html}, eprint = {https://eja.journals.ekb.eg/article_92446_668b19bf270c461a6aa2ee193422c867.pdf} } @article { author = {Zaghloul, Walaa and Madkour, Fedekar and Mohammad, Samya}, title = {Marine gelatinous zooplankton of the Egyptian waters: a review}, journal = {Egyptian Journal for Aquaculture}, volume = {10}, number = {2}, pages = {35-45}, year = {2020}, publisher = {Blue Resources for Aquaculture, Environment and Society Development}, issn = {2090-7877}, eissn = {2636-3984}, doi = {10.21608/eja.2020.94283}, abstract = {Gelatinous plankton is formed by representatives of cnidarians (true jellyfish), ctenophores (comb jellies) and tunicates (salps). Gelatinous groups are a conspicuous, but relatively little studied component of marine ecosystems; in recent years its importance in pelagic food webs has gained increased awareness. They are essential components of the marine food web, relaying primary production from microbial algae to fish and seabirds. Gelatinous zooplankton may cause substantial mortality of fish eggs and larvae. This may play an important role in decreasing fishing stock of commercial fisheries, and they are an important variable in fisheries science and that it cannot be overlooked. The objective of this paper is to review a current knowledge on gelatinous zooplankton in the Egyptian waters of Mediterranean and Red Seas.}, keywords = {Gelatinous zooplankton,jellyfish,Cnidarians,Ctenophores,Red Sea,Mediterranean Sea}, url = {https://eja.journals.ekb.eg/article_94283.html}, eprint = {https://eja.journals.ekb.eg/article_94283_73d97d73a1ecfcb54a24ad266d6e8566.pdf} } @article { author = {Ahmed, Kareem and Ibrahim, Mohamed and Mounes, Hossam}, title = {Effect of using low molecular weight Chitosan on water quality, quality indices and stress reduction of Nile tilapia}, journal = {Egyptian Journal for Aquaculture}, volume = {10}, number = {2}, pages = {47-65}, year = {2020}, publisher = {Blue Resources for Aquaculture, Environment and Society Development}, issn = {2090-7877}, eissn = {2636-3984}, doi = {10.21608/eja.2020.30379.1023}, abstract = {The study investigated the efficiency of adding extracted chitosan from shrimp wastes to enhance water quality, reduce stress and enhance tilapia flesh quality. Water quality parameters showed no significant differences among all treatments in (Dissolved oxygen, Temperature, pH, NO2 and Orthophosphate values). Treatment fish water with chitosan affected some nitrogenous parameters such as NH3 and NO3, where the values were (0.7, 0.6, 0.1 and 0.5 mg / l) for NH3, and (0.62, 0.61, 0.36 and 0.59 mg / l) for NO3, respectively. The lowest value of NH3 and NO3 was recorded in T3 (15 mg / l chitosan) followed by T4 (20 mg / l chitosan), T2 (10 mg / l chitosan) and finally T1 (negative control). Chemical composition of the samples revieled that the adding chitosan to the water improved moisture, protein, fat and increased ash content for fish flesh respectively, followed by control. Physiochemical quality parameters such as pH, acid value, Free amino nitrogen (FAN), Free fatty acids (FFA), total volatile bases nitrogen (TVB-N) and trimethylamine (TMA-N) showed that the addition chitosan reduce the increase in this parameters of the three treatments compared to the control The blood chemistry indices revealed that; T3 had the lowest AST; T4 had the lowest ALT values compared to control and T2, respectively. Despite the variation in Alb, Glob and ALP values among treatments they showed no significance differences. T3 showed the lowest values among all treatments for GLU, CHO, HDL, LDL and TG followed by T4, T2 and control, respectively.}, keywords = {Chitosan,tilapia,water quality,Chemical composition,Physiochemical parameters and Stress reduction}, url = {https://eja.journals.ekb.eg/article_107482.html}, eprint = {https://eja.journals.ekb.eg/article_107482_6cfe954824688cb7bea6e9af2b3b880d.pdf} }