Papers by mohamed el-magsodi
Kielitiede Ennen Ja Nyt
Suomalaisen Kirjallisuuden Seura, 1966
Thesis submitted in fulfillment of the requirements for the degree of Doctor (PhD) in Applied Bio... more Thesis submitted in fulfillment of the requirements for the degree of Doctor (PhD) in Applied Biological Sciences : Aquaculture
Aquaculture International, 2015
The brine shrimp Artemia franciscana is an important live feed for fish and shellfish larvicultur... more The brine shrimp Artemia franciscana is an important live feed for fish and shellfish larviculture. Cysts of Artemia are naturally found in a wide variety of harsh environments worldwide where they are exposed to different changing environmental conditions. Artemia cysts are also exposed to different hydration/dehydration (H/D) conditions during the post-harvest processing period in the Artemia processing industry. In this study, cysts of two strains of A. franciscana originating from two different geographical locations-one a natural population from Great Salt Lake (GSL), Utah, USA, and the other cultured in the Vinh Chau (VC) salt ponds, Vietnam-where they experience different environmental factors, were exposed to successive hydration/dehydration (H/D) cycles with the aim of determining the effects of these conditions on the stress (i.e., induction of Hsp70) and functional (i.e., resistance toward abiotic and pathogenic biotic factors) responses of the emerged nauplii. Our results showed that a short period of H/D of the cysts did not appear to have a deleterious effect on the emerged nauplii of both strains, as was evidenced by the absence of significant difference in the survival of nauplii emerged from the control and treated cysts, upon challenge with a thermal stressor or with pathogenic Vibrio campbellii. A limited exposure to H/D treatment even leads to the induction of enhanced thermotolerance in GSL nauplii. In essence, these observations add some insights to our current understanding of stress responses in Artemia under the described experimental conditions. In addition, the impact of H/D cycles associated with stress response should be taken into consideration when Artemia is considered as a model organism for future research and applications.
The Salt Marsh (Sabkha) in the Western Part of Libya
Tasks for Vegetation Science, 2010
The total coastline of Libya is about 1975 km long. Numerous salt marshes bordered by sabkhas occ... more The total coastline of Libya is about 1975 km long. Numerous salt marshes bordered by sabkhas occur along the coast. These sabkhas cover some a very large area on the coast line and most of them are completely dry during the summer season. One of the larger sabkhas is located in the western part of Libya and is called “the
Nauplii hatching from Artemia cysts are crucial in larviculture nutrition. Artemia cysts may be e... more Nauplii hatching from Artemia cysts are crucial in larviculture nutrition. Artemia cysts may be exposed to repeated hydration/dehydration (H/D) cycles pre-harvesting or during processing and storage. To observe the effect of these cycles on cyst quality, Artemia franciscana cysts were exposed to a comprehensive set of various H/D treatments, differing in the number of cycles (1, 2, or 3) and the duration of the freshwater hydration period (2 or 4 h). Cyst quality was assessed using the criteria of immediate relevance for aquaculture use, such as hatching percentage directly after H/D treatment and after-18°C storage up to 1 month, longevity of axenically hatched starved nauplii, cyst and naupliar energy content, and (for the most extreme H/D treatment) cyst and naupliar fatty acid and vitamin C content. Repeated H/D cycles resulted in significantly (P \ 0.05) decreased cyst hatching, reduced starved naupliar longevity and individual energy content, loss in vitamin C and fatty acid content, and moreover a close correlation between these parameters as a function of progressive H/D treatments. This is of immediate relevance for aquaculture nutrition, as commercial Artemia cysts may have gone through an unknown sequence of H/D cycles in nature or in the processing line, which affects the nutritional quality of the nauplii used in larviculture operations.
Reproductive and lifespan characteristics of Artemia from Libyan Abu Kammash Sabkha
Libyan Journal of Marine …, 2005
... Mohammed Hamza 1; Usama A. Drebika 1; and Patrick Sorgeloos3 ... western United States major ... more ... Mohammed Hamza 1; Usama A. Drebika 1; and Patrick Sorgeloos3 ... western United States major transbasin-water diversions and other alterations have caused salinity to increase in Mono-lakes, California, Pyramid Lake, Nevada, Great Salt Lake, Utah (Mason, 1967; Winkler et ...
Libyan Journal of Marine …, 2005
19 LIBYAN JOURNAL OF MARINE SCIENCE (2005) 10:19-J ... , .".. .Mohamed O. EI..Magsodi1; Hass... more 19 LIBYAN JOURNAL OF MARINE SCIENCE (2005) 10:19-J ... , .".. .Mohamed O. EI..Magsodi1; Hassan M. EI-Ghebli1;' Mohammed Hamza 1;Gilbert Van Stappen2 and Patrick Sorgeloos2. ... 1Marine Biology Research Center POBox: 30830~Tajura, Tripoli, Libya ...
Journal of Crustacean Biology, 2016
We investigated the effect of illumination on the hatching of eggs of one strain of Artemia franc... more We investigated the effect of illumination on the hatching of eggs of one strain of Artemia franciscana Kellogg, 1906 and two strains of parthenogenetic Artemia (Branchiopoda, Anostraca). The following light parameters were used: colour (red, blue, and white light, having different intensities in the range 22-27 μmol E/m 2 per s, corresponding with different wavelengths in the range 400-700 nm), and additionally (Experiment 1) duration of light exposure (varying between 15 min and continuous light) or (Experiment 2) timing of light exposure (from the 1 st to the 13 th hour of incubation of eggs for hatching). Continuous darkness was included as negative control. Hatching percentage was determined after 24 and 48 h, and additionally after 72 h in Experiment 2. For all samples a relatively short exposure to light (6 h or less) during the initial hours of incubation maximally triggered the hatching process; 1 h of light had highest efficiency when given during the 4 th hour of incubation of eggs for hatching, and less so when supplied earlier or later. Lower sensitivity was observed for the red light spectral region (600-700 nm), with mostly limited differences between blue (400-500 nm) and white (400-700 nm) light. Differences between samples could be linked to factors such as chorion thickness, pigmentation, storage conditions, diapause status and genotypic differences in general, but to what extent each of these factors contributes to the variability among the strains needs to be studied by analysing a more comprehensive set of samples. The fact that the inter-strain differences observed in our study were only of quantitative nature nevertheless suggests that light triggers hatching in Artemia eggs through a process that is consistent throughout the genus. Our work could contribute to a better understanding of the hatching biology of dormant life stages in Crustacea in general.
Uploads
Papers by mohamed el-magsodi