Reproduction of the Egyptian sole, Solea aegyptiaca (Actinopterygii: Pleuronectiformes: Soleidae), from Port Said, Egypt, Mediterranean Sea

Background. Understanding of reproduction of the Egyptian sole, Solea aegyptiaca, has been considered a major step toward understanding its population dynamics, especially in the eastern Mediterranean Sea. In Egypt this species has highly commercial value and it has recently been successfully bred in aquaculture, but more data on the reproductive biology is still needed. So, the present work aimed to study the population structure and the reproductive dynamics of S. aegyptiaca over an annual reproductive cycle. Materials and methods. A total of 594 specimens of S. aegyptiaca were obtained from October 2004 to September 2005 in a monthly basis from the commercial catch. Sex ratio, age, and length at first maturity, gonado-somatic index, maturity stage, oocyte diameter, and fecundity were analysed in order to increase our knowledge on the reproductive dynamics of S. aegyptiaca. Results. The overall ratio between males and females was 1.0 : 1.15 and showed no significant deviation from the expected 1 : 1 ratio, males are dominant among small size, while females are dominant among larger size. Females attained their maturity at the length of about 15.0 cm. The reproductive activity of S. aegyptiaca took place between January and June with a peak on January, when the majority of oocyte growth (> 400 μm in diameter) occurred. Hydrated oocytes reach 1000 μm immediately before spawning. Absolute fecundity ranged from 9898 to 38505 and can be expressed as a function of total length. Conclusion. S. aegyptiacais a winter spawner, and the female attains its maturity at 15.0 cm of total length. So, fishing should be prohibited during the period from January to June to conserve the existing stock of the target species. Regulations should also be directed to reduce the fishing potential of 18.0 cm total length. It is important to give each fish the chance to reproduce at least once in its lifetime

Evaluation of the viricidal efficacy of commercially used disinfectants against Newcastle disease virus

The aim of this study was to evaluate the viricidal action of fourteen commonly used and commercially available disinfectants on poultry farms and are belonging to different groups of biocides against Velogenic Newcastle disease virus (NDV). Evaluation was carried on two different surfaces (cement and rubber) contaminated experimentally with Newcastle disease virus. Reliable disinfectants should pass the test if at least 2.8 log reductions were achieved, and no recoverable viruses were isolated after the treatment, the last point is very important in the evaluation as although the direct reduction in virus titer is critically needed in terminal disinfection, the recovered virus after disinfection or shed virus after vaccination will be always capable of introducing infections. Our results revealed that three disinfectants out of fourteen were able to achieve the previous test criteria 1. Calcium hypochlorite (5.5 log reduction on cement coupons, and 4.38 on rubber coupons) 2. Halamid ® (5.5 log reduction on cement coupons, and 4.38 on rubber coupons) and 3. ZixVirox ® (5.5 log reduction on cement coupons, and 4.38 on rubber coupons) while Virkon S ® , PIQuat 20 ® , Synergize ® +Formalin, and GroundZero ® had only achieved the required log reduction on both surfaces but failed to stop viral propagation, it’s also worth to mention that disinfectants Aquazix E52 ® and FumagriEffisafe ® achieved the required log reduction on cement surface only but also failed to stop viral replication, disinfectants Synergize ® , Formic, and Citric acid neither achieved the required log reduction on both surfaces, nor stopped the virus propagation after treatment. © 2017 @ author (s)

Analysis and interpretation of aeromagnetic data for Wadi Zeidun area, Central Eastern Desert, Egypt

The current study is mainly concerned with the analysis and interpretation of the available aeromagnetic data using different advanced processing techniques, to map the subsurface structural framework and depth estimation of these structures of the Wadi Zeidun area, Central Eastern Desert. The visual inspection of the RTP aeromagnetic map defines a rapid change in the subsurface geologic conditions in the form of the lithological characters and tectonic inferences. The shallow sources can be separated from those of deeper causatives, using power spectrum transformation tool. Two methods for locating magnetic sources, Source Parameter Image and Analytical Signal to identifying the properties of their sources indicated that, the depth calculation from the used tools ranges between 900 and 3000 m as the average ranges. Also, the comparative study among the 2D magnetic modelling was established by two profiles constructing. The mapped basement tectonic map is affected by a set of faults trending mainly in the N-S, NE-SW, NW-SE and ENE-WSW direction. Keywords: Wadi Zeidun, RTP magnetic data, Power spectrum curve, Source Parameter Image, Analytical Signal, 2-D modellin