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The objective of this study was to follow up the growth performance and gonads development of sex reversed male Nile tilapia. Fish fed commercial diet contained 30% crude protein at a rate of 3% of the biomass and 10 fish were randomly taken biweekly during the experimental period (16 weeks). Growth performance, feed utilization and survival rate were calculated. Histological examination of the gonads was done every two weeks to follow the growth and development of the gonads. Results showed positive interactions between growth parameters and reproductive development during different periods of fish productive cycle. Histological examination illustrated that during early ages, testicular sections of mono sex male’s tilapia had abnormal architecture with deterioration of germinative tissue. Despite abnormal testis texture, fish started spermatogenesis, a step toward puberty when their body weight reached 29.16g. As fish reached 4-5 months, male start to recover their testes normal structures and at age of 5.5-6 months, testicular sections appeared normally as pointed out by firmed testicular lobules, existence of all germ cell types and the intensively stored spermatozoa in testicular lumen and testicular ducts, confirming the full maturity of males. Based on the obtained results, it can clearly conclude that there is a relationship between age, body weight and development of sexual glands. It has also been shown that the hormonal treatment of tilapia seeds in the early stages for production of mono sex (all males) leads to a marked deterioration in the testes structure, continues near the fish enters the sexual maturity. At a later age, males can overcome this deterioration, restore the histological structure of the testes and achieve full sexual maturity at the age around from 5.5 to 6 months.

The study was carried out at Faculty of Agriculture, Ain Shams University to assess the effect of two of algae species (Arthrospira platensis and Nannochloropsis gaditana) on growth performance of monosex tilapia fish (Oreochromis niloticus), fish were fed on a basal diet supplemented with 0,3,5,7% of each algae. To perform seven experimental treatments were assigned in three replicates each. The experiment was designated as follows: (T1) control (without algae), (T2) basal diet supplemented with 3% spirulina (spiru 3), (T3) basal diet supplemented with 5% spirulina (spiru 5), (T4) basal diet supplemented with 7% spirulina (spiru 7), (T5) basal diet supplemented with 3% Nannochloropsis (nanno 3), (T6) basal diet supplemented with 5% Nannochloropsis (nanno 5) and (T7) basal diet supplemented with 7% Nannochloropsis (nanno 7). Experimental tanks were a part of closed recirculating system, where almost constant environmental conditions were kept throughout the experimental period. Twenty-one quadrate fiber glass tanks with 108-liter water capacity were stocked with 15 fish per tank. The individual initial body weight (2.7 g) was recorded at the beginning of the experiment. All fish in each tank was weighed every two weeks during the whole experimental period. The fish were fed the experimental diet for 95 days Results indicated that nanno 5 treatment had higher significant trend (P

This study aimed to investigate the effect of different concentrations of different water salinity (36, 17, 8, 4, 2 ppt. and salinity level is less than 1ppt.) on growth performance and survival rate (%) of sea bass fry Dicentrarchus labrax. One thousand and two hundred sea bass fry were randomized stocked at twelve indoor tanks; 4 m3 each (two replicate/treatment), with an average initial body weight of (2 ± 0.30 g/fish) at the rate of 100 fish / tank. Fish in each tank were hand-fed with commercial diet (40 % crude protein and 485.582 Kcal GE/ 100 g diet). Fish were fed daily at a rate of 15, 10, 5, 4 and 3% of the body weight daily for the (1:2.2); (2.2:3.84); (3.84:9.2); (9.20:12.70) and (12.70) g/fish : until the end of the experiment, respectively. The daily allowances were divided into three meals at 8.00 am; 11.00 am and 2.00 pm. Fish were fed six days a week throughout the experimental period (167 days). The daily amount of feed was re-adjusted every two weeks according to the actual fish biomass in the tanks. The highest significant values of growth performance parameters were observed when sea bass fry were reared at salinities 8 and 36 ppt. Weight gain of the other treatments were negatively affected (p

The relative importance of fish in Egypt increased from 1482 thousand tons in 21001 to 15525 thousand tons in 2014, an increase of 43 thousand tons or about 2%. The fish are characterized by fluctuations in productivity and price, which affects the production and marketing decisions of both the producer and the consumer and lead to the emergence of problems and difficulties in marketing, the most important lack of marketing information and the modest marketing services available on the market and the high share of marketing intermediaries of the consumer price and requires study of the marketing side of the transit market. And used the standards for calculating the marketing margins and the distribution of consumer pounds and the same seasonal analysis of the prices of the most important types of fish during 2010-2014. The research was based on the primary data collected from the market as well as the secondary data obtained from the market management and then the selection of the types of tilapia and crustaceans as the most important types of fish, such as the high market value and demand. The share of the product in the 2014 retail price was about 83% while the wholesaler's share was about 64% while the retailer's share was 11.66% of the retail price. While the share of the wholesaler was 4.6%, while the share of the wholesaler was 19.4%. The efficiency estimate for the marketing costs of the tilapia category according to the variable yield index was 1020%. Therefore, the efficiency can be increased. To 90% which reflects the lack of efficiency and this during 2009 and then increased efficiency to reach a maximum of 100% in 2012-2014. The results of the efficiency assessment of the marketing costs of the cutters according to the variable yield scale of the minimum threshold of 0.5% and thus the efficiency can be increased to 95% which reflect the lack of efficiency and this during 2005 was the best efficiency during the years 2012-2014. The results of the IRS indicate increased marketing costs to improve efficiency during the year 2001-2011 and there was a reduction in costs in 2012 and the efficiency was high. In 2013 and 2014, there was a decrease in the independent variable from decreasing the difference with efficiency stability to reach the same efficiency. For tilapia. The results of the IRS show that the marketing costs to improve efficiency during the period 2001-2011 should be increased for catfish and there was a decrease in costs in 2012 and there was high efficiency. In 2013 and 2014 there was a shortage in the independent variable, Efficiency of access to the same efficiency. On the other hand, the minimum season of wholesale prices of tilapia during the years 2010-2014 in the months (October- November- August) and the maximum during the months (April- May- February), (October- December- November) and the upper limit (April- June- March). The most important marketing problems of fish in the absence of equipment market fish keeping 'weak regulation of the market lack of control on the actual functioning of the auctions market spread of the phenomenon of indiscriminate sale without a license, which requires regulation of dealing in the market and provide the appropriate equipment and provide data and market information for the services of all workers in the market.

The present experiment was conducted to evaluate the effect of acidifiers on growth performance and immunity of the African catfish C. gariepinus. This experiment was carried out in the wet lab of Fish Production Branch, Department of Animal Production, Faculty of Agriculture, Ain Shams University. A total of 120 fish were selected as healthy catfish which had a uniform size and average weight of 94.93 ± 0.89 g. A thirty of catfish were used in each treatment divided into three replicates as (10 fish/ quadrate tank). Four experimental diets were formulated at 35 % crude protein with different levels of organic acid blend (OAB); diet was supplemented with 0, 2, 4 and 6 ml of organic acid per kilogram diet. Growth parameters, apparent digestibility of crude protein and ether extract were measured. The chemical proximate analysis for whole-body of fish was conducted at the end of the experimental period. Hematological parameters of fish and liver function enzymes were also measured. The fish group fed on 0.6 % organic acids blend showed the highest significance (P < 0.05) increase in total weight gain (438 ± 14.24 g), specific growth rate, best feed conversion ratio, feed efficiency ratio and highest protein efficiency than the rest of experimental groups. The highest apparent digestibility for crude protein were achieved in the third fish group which fed diet supplemented with acidifiers at 4 ml / kg diet and have significant difference (P < 0.05) with other groups. Data obtained in hepatosomatic index % showed no significant difference among different treatment refers to the health status of liver. However, ALAT and ASAT recorded high values in the higher group of OAB-treated fish indicating that liver could be affected. Hematological parameters were in normal range except for PCV, Hb, RBCs, and WBCs count which were decreased in the high dose of treated fish. Finally, it could be concluded that using of acidifiers as feed additives at lower doses can enhance growth, productivity and immunity of the African catfish (C. gariepinus).

This study aimed basically at identifying the level of rural women adoption of environmental practices in Menufiya Governorate. This main obective was achieved throw the followinge sub-objectives : determining the environmental knowledge level of rural women, identifying the dgree of rural women application of environmental practices, determining the factors which correlated with each of the environmental knowledge level and dgree of rural women application of environmental practiece. The study was carried out in two villeges in Menufiya Governorate, the first villege was Monshiat Bakhaty which belongs to Shebien Elkom district and the sconede villege was Sahel Elgawaber which belongs to El shohadaa district. 100 rural women were selected randomly from each village. The study findings were: the environmental knowledge level was high as 83.5% from respondents. About 47% from respondents were applying the environmental practices. There were four independent variables (social participation, culturel cosmoplitness, geographical cosmoplitness, age) explained together 16.3 % of the total variance of the environmental knowledge level. There were six independent variables (family monthly incom, environmental situation at the village, cultural cosmoplitness, family education, geographical cosmoplitness, environmental knowledge) explained together 55.5% of the total variance of the environmental application dgree.

Solid-phase extraction (SPE), gas chromatography electron capture detector (GC-ECD) and gas chromatography nitrogen-phosphorous detector (GC-NPD) and gas chromatography–mass spectroscopy (GC-MS) were applied for trace-level de-termination of 20 pesticides in river nile water. Samples were collected from March to October 2003 from different sites located in Greater Cairo, Egypt. First, extrac-tion by on-site solid-phase extraction of 1 liter from field and laboratory spiked and unspiked (raw river water) samples using poly-divinyl benzene-N-vinyl pyrolidine cartridge based sorbent. Next, water extracts were subject of analysis by GC-ECD and GC-NPD. Next, selected samples that were positive to GC-ECD or GC-NPD were analyzed by GC-MS in order to improve the determination of detected pesti-cides. Recoveries from laboratoy spiked samples were > 85% for 16 of the 20 com-pounds with % relative standard deviation (% RSD) in the 5 to 10 % range. The lowest recoveries were for aldrin, 52 % and prothiofos, 48 %. A similar trend was observed with p,p-DDE and p,p-DDT values. Field spike results also indicated high % recovery for most of the target compounds. Values were > 85% for 12 of the 20 analytes, as was the case in laboratory spikes, Aldrin, 54 % and prothiofos, 55 % yielded the lowest values. Overall field spike recovery reproducibility was lower since % RSDs were higher, 15-40 %. Overall results indicated a relatively high de-gree of accuracy and precision could be achieved for most of the target compounds by methods applied in present study.