الفهرس 
Acknowledgments
Heavy metals pollution indicesOnly 14 pages are availabe for public view
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Abstract
Red Sea has unique marine habitats as coral reefs, mangroves, rocky and seagrass beds. Echinoderms represent an ecologically important group of reef-associated invertebrates that could profoundly affect reef structures in both tropical and subtropical waters. So the present study aimed to highlight the most important ecological characteristics of echinoderm species inhabiting the littoral zone of southern and northern regions along the Red Sea coast of Egypt with reference to heavy metals accumulation and biochemical analysis.
To achieve the goal of the study, echinoderm species were collected from littoral zone in Red Sea by snorkeling and SCUBA diving in the depth reached to 7m. Fourteen sites, (42 locations), were selected along the Red Sea coast. At each location the abundance of echinoderms was calculated using (10×10m) quadrate with five replicates during the period from February 2016 to August 2017. Some ecological factors including air and Sea water temperatures (°C), water hydrogen ion concentration (pH), Sediment Grain Zize analysis, Total Organic Matters (TOM%), Carbonates content (CO3%) and some heavy metals concentration (Fe, Mn, Zn, Cu, Ni, Pb, and Cd ) were recorded seasonally for four main sites during 2016.
The results showed variations of investigated ecological factors at different four main sites during different seasons of study. These differences between sites were statistically significant for all studied factors except in case of pH and TOM. While the differences of ecological factors among seasons were not significant in case of pH, TOM, MSG and Ni. Zn, Cu and Cd concentrations in sediment. There were significant differences between the main sites in Cumulative Sediment Criterion Units (CSCU). Al-Hamraween was more polluted site compared with other sites. This pollution can be related to phosphate mining. Total Organic Matter recorded higher value in Safaga (Mangrove) while Total carbonate recorded higher value in Ras Gharieb. Coarse Sediment group and Medium sediment group recorded higher value in Al-Hamraween, while Fine sediment group recorded higher value in Hurghada.
Twenty-nine species of echinoderms belonging to 5 classes, 12 orders and 18 families were recorded at Suez Gulf and Egyptian Red Sea coasts from twenty-nine sites. An identification key was prepared for the collected echinoderm species based on morphological characters.
The general survey for Suez Gulf, Egyptian Red Sea coasts and Al-Aqaba Gulf indicated a total of 33 species of echinoderms belonging to 5 classes, 12 orders and 18 families. Class Echinoidea recorded the highest percentage of species composition. Species richness of echinoderms ranged between three species in site 4 and twenty four species in site 1. Species diversity showed changes in different sites. The Shannon diversity (H’) ranged from 0.06 to 2.24. Suez Gulf sites (sites 4, 5, 6 and 7) recorded the lowest values of diversity, while the highest value was recorded at Ras Mohamed site (site 3).
Twenty species of echinoderms belonging to 5 classes, 10 orders and 12 families were recorded, at the four main sites. The density of echinoderms showed spatial variations between the four studied sites. Regarding biodiversity of echinoderms in the investigated sites, Hurghada showed the highest recorded value for the species richness (S) while the lowest value was recorded for Ras Gharieb. The abundance recorded the highest value in Ras Gharieb while it recorded the lowest value in Safaga. Shannon_H recorded the highest value in Hurghada while it recorded the lowest value in Ras Gharieb. Equitability (J) recorded the highest value in Safaga while it recorded the lowest value in Ras Gharieb.
Eight species of Echinodermata was selected to study the concentration and accumulation of heavy metals (Fe, Mn, Pb, Ni, Zn, Cu and Cd) from four major sites in the coastal areas of the Red Sea- Egypt. Regarding the investgatigted heavy metals concentration in echinoderm species, Echinodia recorded the highest values for studied metals. The highest concentration of (Fe) was recorded in Diadema setosum (175.30±0.54 μg/g), while the highest concentrations of (Mn and Cu) were recorded in Echinometra mathaei (8.53± 4.23μg/g, 4.52±1.63 μg/g), respectively. The highest concentration of (Ni) was in Clypeaster humilis (12.63± 0.57μg/g). In the present study, the mean Biomagnification (BMF) of heavy metals in the species was different between species. The highest BMF values obtained for (Fe) was 80.77±1.43 in Ophiocoma scolopendrina. The highest BMF values obtained for (Mn) was 30.30±21.89 in Diadema setosum. The highest BMF values obtained for (Pb) was 146.78± 164.19 in Bohadschia vitiensis.
In the present study, the highest percentage of saturated fatty acids (SFA) was in Holothuria nobilis and the lowest percentage was recorded in Holothuria scabra. The highest percentage of monounsaturated fatty acids (MUFA) was recorded in Pearsonothuria graeffei while the lowest percentage was recorded in Holothuria atra. The highest percentage of polyunsaturated fatty acids (PUFA) was recorded in Holothuria nobilis and the lowest percentage was recorded in Holothuria atra. The highest percentage of omega-3 fatty acids was recorded in Stichopus herrmanni, and the lowest percentage was recorded in Diadema setosum. The highest percentage of omega-6 fatty acids was recorded in B. vitiensis and the lowest percentage was recorded in Holothuria atra. The present study proved that sea cucumber has great nutritional value.
Nonessential amino acids (NEAA) overall all species were highest for Glycine and lowest for Serine while Essential amino acids (EAA) were highest for Arginine and lowest for Cysteine. All of the NEAA were found at highest concentrations in S. herrmanni except for proline. Essential amino acids were Histidine, isoleucine, phenylalanine, and leucine was high in Pearsonothuria graeffei. Tyrosine, valine, threonine, arginine were high in Stichopus herrmanni.