http://hdl.handle.net/1834/999 Thu, 09 Feb 2012 14:15:07 GMT 2012-02-09T14:15:07Z http://www.oceandocs.org:80/retrieve/4020/egypt-ss.jpg http://hdl.handle.net/1834/999 http://hdl.handle.net/1834/2201 Title: Steroid hormone in serum of male mugil cephalus from lake quaron in relation to ultrastructure of steroidogenic secreting tissue Authors: El-Gharabawy, M.M.; Fahmy, A.F.; Assem, S.S. Abstract: The grey mullet (Mugil cephalus) is one of the most common fish species in the Mediterranean Sea. Morphological and histological studies on testes of this species indicate six successive maturity stages. The specific changes in serum sex hormone levels were found to occur during the different phases of gonadal development. Concentration of serum steroid hormone in male Mugil cephalus revealed a marked drop in serum steroid (estradiol and testosterone) hormone levels in nearly ripe stage when compared with ripe stage, while the concentration of estradiol, testosterone and progesterone at late stage (ripe stage) of sexual maturity was increased. Histological examination and cyclic change in the testes were revealed of active spermatogenesis with all generations in the early stages of testicular development. Nearly ripe testes showed more active spermatogenesis, nests of spermatocytes and small number of spermatids. While at ripe stage, the seminiferous lobules contained a fair quantity of spermatozoa with little spermatids. Ultra-structural examination showed well differentiated interlobular connective tissues which noticed at early stages. In nearly ripe stage, the fine structure revealed that early spermatids have round shaped vacuolized cells, a spherical nucleus with diffuse chromatin and without mitochondria. At this stage the interlobular connective tissue were hypertrophied, increase in thickness and filled with abnormal fibers. The abnormal shape of interlobular tissue was observed. Ultra-structurally, all the spermatozoa cells were deformed in shape, characterized by small ovoid or spherical nucleus with highly compact chromatin, surrounded by thick tissue appeared with two deformed mitochondria. In the present result, the concentration of steroid hormone in Mugil cephalus in Lake Quaron was highly correlated with the dysfunction of gonadal hormone, maturation of gametes and considered as good sign of infertility and shortage in secretion function of these tissues may be due to unsuitable environmental condition in Lake Quaron needed for spawning of male. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/1834/2201 2007-01-01T00:00:00Z http://hdl.handle.net/1834/2210 Title: Influence of barley straw and submerged macrophytes on fishpond wastewater quality Authors: Ghobrial, M.G.; Okbah, M.A.; Gharib, S.M.; Soliman, A.M. Abstract: Barley straw has received, recently, considerable attention as an algicide, which could be used to control algal growth in fishponds. It is regarded as cost-effective, user friendly and environmentally sounds. On the other hand, the submerged wetland macrophytes are crucial for the stabilization of clear water state in shallow lakes, by their active production of anti-algal compounds (allelochemicals) through allelopathy. Microcosm experiments using barley straw and the submerged macrophytes: Najas marina L., Potamogeton pectinatus L. and Ceratophyllum demersum L. in culture media with fishpond water were carried out outdoors to simulate the situation as natural as possible. Nutrients concentrations were measured beside the analysis of phytoplankton and zooplankton communities were analyzed during nineteen days incubation period. Nitrogen and phosphorus elements were determined in the tissues of used aquatic macrophytes at the beginning and by the end of the experiment. Multivariate statistical assessment using matrix correlation and principal components analysis was applied for interpretation of the experimental data. Principal component PC1 in barley straw medium accounted for about 47% of the total variance with strong correlation between selected parameters and a positive coefficient (r = 0.94 and 0.84) for diatoms – PO4 and diatoms – SiO4 respectively. On the other hand, PC1 in the status of N. marina and C. demersum contributed to 46% and 58% of the total variance, respectively with high positive loading between diatoms and green algae, while in case of P. pectinatus PC1 accounted for 62% of the variance with positive loading for chlorophyll – a, green algae and rotifers. Thus, rotted barley straw stimulated the growth and dominance of diatoms, rather than the green algae, throughout the incubation period. In the mean time, the macrophytes had allelopathic impact on the diatoms community, particularly Najas, while stimulated growth of the green algae. Zooplankton community was dominated by rotifers in all macrophytes media, while protozoan dominated barley straw medium. Complete depletion of nutrients was detected after few days in all media, while oxygen sustained acceptable levels. Phytoplankton assemblages shifting from green algae dominance to diatoms in barley straw medium is recommended as an invention to provide an integrated bioremediative product with readyto-use. Active biological compounds (algicides) derived from barley straw were more reliable than allelochemicals from aquatic macrophytes. Through their beneficial effects they would render aquatic environments such as, ponds, lagoons, aquaria, aquaculture systems, wastewater treatment, holding or conveying systems more aesthetically pleasing, efficient in aquatic animal production, and less susceptible to algae and other undesirable aquatic plants. They would thus require less maintenance. It is a tentative suggestion to use barley straw for field manipulation experiments. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/1834/2210 2007-01-01T00:00:00Z http://hdl.handle.net/1834/2200 Title: Biodegradation kinetics of bromoxynil as a pollution control technology Authors: Askar, A.I.; Ibrahim, G.H.; Osman, K.A. Abstract: Nonpoint source (NPS) pollution from agriculture is the leading source of impairment to Survey Rivers and lakes. Pesticides are one of the major NPS pollutants that result from agricultural activities. Among those pesticides, is Bromoxynil (BRMX) which is a widely used herbicide. The present study was carried out to determine the capability of selected biological control agents to degrade BRMX at different incubation periods. Microbial degradation of BRMX at the rate of 100 ppm in pure liquid culture media of either seven isolates of bacteria; Azotobacter chroococcum, Azospirillium barasilense, Klebsilense pneumoneae, Pseudomonas cepacia, Pseudomonas fluoresences, Bacillus subtilis, and Bacillus polymyxa or two isolates of fungi; Trichoderma viride and Trichoderma harzianum has been determined at different time intervals using high performance liquid chromatography (HPLC) with UV detection, and solid phase extraction (SPE) technique. A biphasic model was assumed in order to carry out the statistical study of the loss of BRMX from the media enriched with either bacteria or fungi. The results showed that, the percentages of residual amount of BRMX from media enriched with bacteria ranged from 29.51 -71.94, 18.89-43.88, 9.82-35.07, 3.47-31.90 and 1.80-19.24% after 3, 7, 14, 21 and 28 days of incubation, respectively. On the other hand, the residual amount of BRMX from media enriched with fungi ranged from 45.61-60.26, 21.25-30.56, 6.48-20.63, 1.25-10.49 and 0.63-1.56% after 3, 7, 14, 21 and 28 days of incubation, respectively. The data indicate that there was a faster rate of BRMX loss in the first phase than the second one. This is clearly reflected in the t1/2 values. Therefore, it is recommended to use these microorganisms as biological control agents for the integrated pest management (IPM) programs to reduce agricultural non point source (NPS) pollution to prevent pesticides from reaching ground and surface water. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/1834/2200 2007-01-01T00:00:00Z http://hdl.handle.net/1834/2207 Title: Comparative study on octopus vulgaris (cuvier, 1797) from the mediterranean and red sea coasts of egypt Authors: Riad, R.; Gabr, H.R. Abstract: Specimens from common octopus, Octopus vulgaris captured from the Red Sea and Mediterranean Sea showed significant differences in four of seven morphometric measurements .These differences are sufficient to recognize the populations of this species in the two habitats. The computed length-Wight relationship and condition factor for common octopus in both areas showed that representatives of this species from the Red Sea are heavier than those captured from the Mediterranean Sea for the same length group. Moreover, the natural mortality coefficient of Mediterranean representatives was comparatively higher than for the Red Sea octopus. This shows that the environmental conditions in the Red Sea are more suitable for O. vulgaris than in the Mediterranean Sea. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/1834/2207 2007-01-01T00:00:00Z