http://hdl.handle.net/1834/1000 Wed, 19 Jun 2013 02:21:18 GMT 2013-06-19T02:21:18Z http://http://www.oceandocs.org:80/retrieve/3248/egypt.gif http://hdl.handle.net/1834/1000 http://hdl.handle.net/1834/1455 Title: Vertical migration of zooplankton groups in an Eutrophic bay, Dekhaila harbor, Alexandria, Egypt Authors: Abdel-Aziz, N.E. Abstract: Diel vertical migration of different zooplankton groups in Dekhaila Harbor was studied monthly from May 2003 to April 2004. Generally, more groups were found in the surface layer (0-10 m.) than the deeper one (10-20 m.). Some zooplankton groups undergo significant vertical migration at certain time of the year, others showed no clear differences in distribution patterns and exhibited no directed movement patterns. Some species stayed a part of the day within certain layer of the water column, others were randomly dispersed in the whole water column during different hours. Responses appear to depend also on the life stages of each zooplankton group, as well as other ecological conditions such as temperature, light and amount of food. Population budget indicates that the abundance of some groups was greater at the morning time, others at the sunset time. While the noon time often showed lower density. The time of the day which showed the lowest count of each group is known as the day deficit, which is probably due to diel horizontal migrations.; استهدف البحث دراسة الهجرة الرأسية اليومية لمجتمع الهائمات الحيوانية في ميناء الدخيلة الذي يقع داخل خليج المكس على ساحل البحر المتوسط غرب الإسكندرية , حيث أجريت هذه الدراسة على عينات شهرية جمعت لمدة عام في الفترة من مايو 2003 إلي إبريل 2004 من عمقين 0-10 ,10-20متر كل ساعتين خلال ساعات النهار و ذلك من محطة ثابتة . و قد تميز مجتمع الهائمات الحيوانية بكثافة عالية في الطبقة العليا0-10م أكبر من الطبقة العميقة 10-20م و يرجع ذلك إلي زيادة شدة الأستضاءة و التركيز العالي للكلوروفيل في هذه الطبقة و بينت بعض المجاميع هجرة رأسية واضحة في وقت معين من العام بينما لم تبد أخري أي نوع من الهجرة الرأسية. كما أن بعض الأنواع تركزت في وقت معين من النهار في طبقة معينة من الماء بينما تواجدت أنواع أخري على عمق معين طوال ساعات النهار المختلفة و يعزي ذلك إلي الاختلاف في كمية الضوء و درجة الحرارة . كما أظهرت بعض هذه الكائنات كثافة عالية خلال ساعات الصباح و البعض الآخر عند ساعات الغروب بينما كان وقت الظهيرة غالبا يمثل الكثافة المنخفضة . وكذلك فقد دلت النتائج على وجود وقت معين من النهار تكون فيه كثافة كل مجموعة أقل ما يمكن و علل ذلك بسبب الهجرة الأفقية اليومية , كما أبدت بعض المجاميع توزيعا معين اعتمد على المرحلة العمرية لها و أيضا على الظروف البيئية السائدة مثل الحرارة و الضوء و كمية الغذاء الموجود بالماء. وعموما فقد اعتمدت الهجرة الرأسية لكل كائن على سرعته والاختلافات الفسيولوجية بين الأجيال المختلفة. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/1834/1455 2006-01-01T00:00:00Z http://hdl.handle.net/1834/1221 Title: Validation of length frequency analysis for boops boops (bogue) growth estimation Authors: El-Haweet, A.; Hegazy, M.; Abu-Hatab, H.; Sabry, E. Abstract: Scales reading and length frequency distribution were used for age determination and growth estimation of Boops boops (Bogue) stock of Western Mediterranean Coast of Egypt. Age determination using scale was done and the time of annulus formation was detected by the marginal increment index. Bhattacharya’s method was used for length frequency analysis. Both methods showed 6 age groups. ANOVA test revealed insignificant differences between both estimates of length at age results. Growth parameters estimated using length-at-age data from both methods confirming the age determination results. Growth performance index indicated high similarity between the two estimates. The results revealed the compatibility of length frequency distribution to scale reading for stock assessment studies of bogue stock in Western Mediterranean Coast of Egypt. Description: This journal is published by NIOF, Alexandria, Egypt Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/1834/1221 2005-01-01T00:00:00Z http://hdl.handle.net/1834/1062 Title: Ultrastructural Of Oncorhynchus kisutch muscle development Authors: Rabah, S. Abstract: In a second study of electromicroscopic analysis of ultrastructural organelles of coho salmon muscle showed a significant increase in lipid droplet density in the largest stages compared with the smallest fish. The opposite was observed with the mitochondria where its density decreased in the large sized fish. An apparent decrease in capillary density with increasing body mass was also observed. These finding may imply a possible additional role of lipid depot as fish grew from parr to smolt. Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/1834/1062 2005-01-01T00:00:00Z http://hdl.handle.net/1834/1296 Title: Toxicity of cadmium and copper and their effect on some biochemical parameters of marine fish mugil sheheli Authors: Abou El-Naga, E.H.; El-Moselhy, K.M.; Hamed, M.A. Abstract: The present work aimed to estimate the toxicity of cadmium and copper to fingerlings of marine fish Mugil seheli, as well as the effect of different concentratios of Cd and Cu on some biochemical parameters (Aspartate and alanine transaminase enzymes, glucose, glycogen, lipid and protein) in the fish organs. 96-h LC50s of Cd and Cu were 5.36 and 1.64 ppm, respectively. Levels of aspartate and alanine transaminase were reduced within 2 days of exposure to different concentrations of Cd (2.0 and 0.5 ppm) and Cu (0.5 and 0.2 ppm) in both plasma and muscle tissue. Glucose was increased reaching the highest values after 4 days of the treatment with Cd and Cu, while muscle glycogen was increased at first days then dropped after 14 days below control level. Generally, total lipids and proteins in plasma and muscle recorded higher values than the control one.The present study showed high toxicity of copper to fish Mugil seheli comparing to cadmium. Description: This journal is published by NIOF, Alexandria, Egypt Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/1834/1296 2005-01-01T00:00:00Z