Black sand along the Red Sea is often composed of volcanic minerals and heavy minerals. The Red Sea region is known for its unique geological features, and black sand beaches can be found in various areas along its shores. The study presents a comprehensive semi-quantitative chemical analysis of black sand samples collected from various locations along the red sea, revealing significant variations in their elemental compositions. The main oxides were identified in each sample, determined through X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses, indicate diverse mineralogical compositions. The spatial distribution of minerals at each site is depicted through mapping. Additionally, Fourier-transform infrared (FTIR) spectra offer information on the functional groups present in the samples, revealing the existence of hydroxyl groups, aliphatic compounds, and adsorbed water molecules. For Qusier …

In Egypt, while many studies have focused on the radiometry and mineralogy of black sands, research on their effects on nearby aquatic organisms is rare. This study aimed to assess the combined effects of heat stress (HS) and black sand nanoparticles (BS-NPs) on renal function, antioxidant responses (TAC, SOD, CAT), neuro-stress indicators (AchE, cortisol), and to conduct histopathological investigations in the kidney and spleen tissues of African catfish Clarias gariepinus over a 15-day period to exposure to control, HS (32 °C), BS (6.4 g/kg diet) and HS + BS groups. The outcomes revealed that thermal stress alone showed no significant difference from the control. However, creatinine and uric acid levels were significantly higher in the BS-NPs and HS + BS-NPs groups (p < 0.001). Antioxidant markers (TAC, SOD, and CAT) were substantially reduced across all treated groups (0.05 ≥ p < 0.0001 …

The water flea, Daphnia magna, serves as a key model organism for investigating the response of aquatic organisms to environmental stressors, including hypoxia. Hypoxia-inducible factor 1-alpha (HIF-1α) is a central regulatory protein involved in the cellular response to hypoxic conditions. In this study, we used CRISPR/Cas9 gene editing to create D. magna mutant lines with targeted alterations in the HIF-1α gene. Mutants demonstrated decreased survival and reproductive output and down-regulated genes for the HIF-1α–mediated pathway in low-oxygen conditions. These findings suggest that the HIF-1α pathway is a critical component of resistance to hypoxia in D. magna. This study provides novel insights into the molecular basis of hypoxia tolerance of HIF-1α in D. magna and expands our understanding of how aquatic organisms can adapt to or be challenged by changing oxygen levels in the face of global …

This study aimed to explore the effects of heat stress and black sand acute exposure on the erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices. Catfish were subjected to black sand nanoparticles (6.4 g of nanoparticles black sand per kg of diet), thermal stress (32 °C), and a combined treatment involving both stressors over a period of 15 days. Catfish exposed to black sand nanoparticles and heat stress singly and/or in combination showed significantly lower red blood cells (RBCs) count, hemoglobin (Hb), platelets, white blood cells (WBCs) count, large lymphocytes, small lymphocytes, and monocytes. Antioxidant indices decreased in black sand NPs and heat stress combination compared to other groups. Notably, the combination of black sand nanoparticles and heat stress led to a substantial increase in the percentages of both RBCs alterations and nuclear abnormalities. Histological examinations of the liver revealed various features, including intracellular bleeding, cytoplasmic vacuolation, tissue deterioration, hepatocyte pyknotic nuclei, nuclear displacement, shrinkage, and accumulation of melanomacrophage cells. In conclusion, the study underscores that the effects of black sand nanoparticles on erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices, become more pronounced under elevated temperatures indicating the potential for synergistic effects between pollution and climate change. This holistic approach is crucial for developing more accurate forecasts of the complex interactions between environmental stressors and their implications for aquatic ecosystems.

Here, we investigate the effects of acute and chronic exposure to arsenate (AsV) and arsenite (AsIII) in the marine medaka Oryzias melastigma. In vivo effects, biotransformation, and oxidative stress were studied in marine medaka exposed to the two inorganic arsenics for 4 or 28 days. An investigation of embryonic development revealed no effect on in vivo parameters, but the hatching rate increased in the group exposed to AsIII. Exposure to AsIII also caused the greatest accumulation of arsenic in medaka. For acute exposure, the ratio of AsV to AsIII was higher than that of chronic exposure, indicating that bioaccumulation of inorganic arsenic can induce oxidative stress. The largest increase in oxidative stress was observed following acute exposure to AsIII, but no significant degree of oxidative stress was induced by chronic exposure. During acute exposure to AsV, the increase in the enzymatic activity of …

There are various substances that can disrupt the homeostatic mechanisms of the body, defined as endocrine-disrupting chemicals (EDCs). The persistent nature of microplastics (MPs) is a cause for concern due to their ability to accumulate in food chains and widespread use, making their toxic effects particularly alarming. The potential of MPs for disrupting the endocrine system was observed in multiple tissues. Moreover, the adrenal gland is known to be extremely sensitive to EDCs, while with the effect of MPs on the adrenal gland has not previously been studied. This study aimed to highlight the potential polyethylene microplastics (PE-MPs) induced adreno-toxic effects rather than exploring the implicated mechanisms and concluding if melatonin (Mel) can afford protection against PE-MPs induced adreno-toxicity. To fulfill the goal, six groups of rats were used; control, Mel, PE-MPs (3.75 mg/kg), PE-MPs (15 …

Endocrine disruptors are synthetic or natural chemicals that can agonize/antagonize hormone receptors or can interfere with the production and secretion of hormones, leading to altered tissue histology and physiology. Pyrogallol is a contaminant widely distributed in aquatic environments that presents health risks to both humans and animals. However, the potential for endocrine disruption by pyrogallol, particularly in fish, are lacking. The purpose of this study was to shed light on how pyrogallol may affect hormone signalling, histopathology, and reproductive outcomes in African catfish Clarias gariepinus. To investigate this, African catfish were exposed to one sublethal concentration of pyrogallol at either 0, 1, 5 or 10 mg/L for 15 days. We then assessed the effects of pyrogallol on the thyroid gland as well as the reproductive system by measuring sex hormone, seminal quality, gonadal histopathology, and …

This study reports the effects of bisphenol A (BPA) on the rotifer Brachionus plicatilis, focusing on growth performance, reproductive output, oxidative stress responses, and lipid metabolism genes. High BPA levels disrupted peak daily offspring production and led to oxidative stress and increased superoxide dismutase and catalase activity. The research identified distinctive monoacylglycerol O-acyltransferase (MGAT) and diacylglycerol O-acyltransferase (DGAT) genes in B. plicatilis, B. rotundiformis, and B. koreanus, enhancing understanding of lipid metabolism in these species. BPA exposure significantly altered MGAT and DGAT expression, and feeding status affected these regulatory patterns. When food was unavailable, BPA reduced DGAT2 and MGAT2a expression. However, under feeding conditions, DGAT2 and MGAT1 levels increased, indicating that nutritional status and BPA exposure interact to affect …

يشكل تغير المناخ العالمي، الناتج عن العمليات الطبيعية والقوى الخارجية والأنشطة البشرية، تهديدًا كبيرًا لرفاهية الإنسان وتنميته. إن ارتفاع منسوب مياه البحر ودرجات الحرارة يجعل مناطق مختلفة غير صالحة للسكن بشكل متزايد، حيث تواجه النظم البيئية البحرية مخاطر كبيرة، لا سيما من حوادث تبيض المرجان. البحر الأحمر، وهو منطقة محيطية حديثة النشأة تشكلت من تباعد الصفيحتين التكتونيتين العربية والأفريقية، يمتد على مسافة 2250 كم تقريبًا في الطول و355 كم في العرض، ويصل إلى أعماق تصل إلى 2200 متر. تتميز هذه المنطقة بمناظر طبيعية قاحلة وتضاريس جبلية. أحد المخاوف الكبيرة بشأن البحر الأحمر هو وجود الرمال السوداء على طول ساحله في مصر. هذه الرمال غنية بالمعادن ذات اللون الداكن مثل المغنتيت والإلمنيت والهيماتيت، والتي يشمل تكوينها السيليكا وأكسيد الحديد وأكسيد التيتانيوم. وقد تم استخدام تقنيات مثل فلورة الأشعة السينية (XRF) وحيود الأشعة السينية (XRD) لتحليل تكوينه. يُسهم تأثير البياض للرمال السوداء، الذي يتميز بضعف قدرتها على عكس الإشعاع الشمسي، في زيادة امتصاص الحرارة والاحترار الموضعي. يؤثر هذا الاحترار على درجات حرارة سطح البحر الأحمر، التي تتأثر بعوامل مثل تفاعلات الهواء والبحر والعواصف الترابية. الآثار البيئية لتعدين الرمال السوداء عميقة، مع مخاطر تشمل تدمير الموائل والتلوث. تؤكد هذه الأنشطة على الحاجة إلى دراسات شاملة وممارسات إدارة مستدامة في منطقة البحر الأحمر. إن معالجة الآثار البيئية المرتبطة بتعدين الرمال السوداء أمر بالغ الأهمية للحفاظ على النظام البيئي للبحر الأحمر. علاوة على ذلك، يُعد التعاون الدولي والممارسات المستدامة أمرًا حيويًا في حماية النظام البيئي للبحر الأحمر من الآثار الضارة لتغير المناخ. من خلال فهم التفاعل بين تغير المناخ والأنشطة البشرية، مثل تعدين الرمال السوداء، وتنفيذ استراتيجيات فعالة للحفاظ عليها، يمكننا العمل على التخفيف من الآثار السلبية على هذه البيئة البحرية الفريدة والحيوية.

This research was carried out for two successive seasons (2022 and 2023) in a private orchard located at Assiut Governorate, Egypt, to evaluate the effectiveness of propolis extract and sodium thiosulfate in maintaining the quality attributes of Saidy date palm fruits during storage. The date palms were 17 years old, grown in a sandy soil, spaced at 8 * 8 meters apart, and irrigated by the drip system. At the end of August, five pre-harvest treatments of date bunches were sprayed as follows:  two concentrations of propolis (3% and 5%) and two concentrations of sodium thiosulfate (0.5% and 1%), in addition to the control treatment (spraying with water). Date bunches were stored at ambient conditions (21 ± 7°C and 60 – 70% RH) for 75 days, and the fruit quality was evaluated every 15 days. The results demonstrated that all quality analyses showed that all applied treatments outperformed the control. Sodium thiosulfate at 1% and propolis extract at 5% were more effective than various treatments Saidy date fruits last longer by lowering the number of fungi, slowing down physiological and weight loss as well as decay. It is delaying changes in total soluble solids, total acidity, as well as total sugars during 75 days of storage at room temperature (21 ± 7°C and 60 – 70% RH) in both seasons.