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To the best of our knowledge, this study is the first to track and demonstrate the mortality event in Diadema setosum (Leske, 1778) along the Egyptian Red Sea coasts. The diadematid is a group of echinoid echinodermates that play an important ecological role in marine ecosystems. However, the current global mass mortality events in Diadema setosum have the potential to significantly change the fundamental structure of the ecosystem. This report was based on the 2023-summer observations of a D. setosum die-off during an ecological investigation in the northern Red Sea, Egypt. To determine the entirety of the event, a group from the Red Sea protectorates carried out an extensive survey simultaneously. The current survey covered the coastal regions of the Elba protectorate in the south, the Wadi El Gemal protected area in the middle, and Hurghada in the north. A diverse population of D. setosum was found dead on the bottom during both snorkeling and scuba diving. Representative photographs were taken at each explored site. Several features were noticed in the dead D. setosum, including a frail body, sand-covered body parts, spines distributed on the bottom, and inactive tube feet. The current findings, therefore, recommend crucially the performance of regular monitoring for the status of D. setosum. In addition, biological and ecological investigations are needed as soon as possible to interpret the causative and potential factors responsible for D. setosum loss. [ABSTRACT FROM AUTHOR]

One of the most significant neglected tropical diseases that have a detrimental effect on economic and public health criteria is Schistosomiasis. Therefore, there is a permanent and urgent need to find alternative means of biological control. Ferula hermonis is a herbaceous plant with various pharmaceutical properties and is known for its endocrine-disrupting effects. The objective of the present study was to investigate the molluscicidal activity of F. hermonis roots methanol extract against Biomphalaria alexandrina snails. The experimental results showed that F. hermonis extract has a molluscicidal activity against adult B. alexandrina snails at LC50 (14.2 mg/l) and LC90 (18.1 mg/l). Exposure of snails to sublethal concentrations LC5 (8.3 mg/l) and LC10 (9.8 mg/l) of the extract considerably lowered snail fertility and egg-laying capacity. In addition, results detected an endocrine-disrupting influence where it caused fluctuations in the levels of the three steroid sex hormones (Testosterone, Estradiol (E2), and Estrogen) following acute and chronic exposure of adult B. alexandrina snails to the sublethal doses of the tested extract. Regarding biochemical alterations, glucose and total lipids levels increased significantly, while protein and albumin contents decreased following exposure to sublethal concentrations, compared to the control snails. The sublethal concentrations (LC5, LC10, and LC50) of F. hermonis roots methanol extract exerted noticeable DNA damage in B. alexandrina snails, whereas LC10 was the most genotoxic concentration with 18.20±0.09% tailed cells and 10.54±0.58 px tail length. F. hermonis roots methanol extract can be considered a promising biocontrol agent against B. alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt, via interference with the reproduction processes, and subsequently reducing the population size of snails in endemic areas. [ABSTRACT FROM AUTHOR]

Schistosomiasis remains a public health problem in many developing countries including Egypt. The disease control initiatives stress on control of snail intermediate hosts side by side with treatment of infected human cases. Blocking the parasite transformation within the snails will interrupt schistosomiasis transmission. Thus, the present study assessed the antioxidant efficacy of Lanistes carinatus tissue extracts and its role as immunostimulant for Biomphalaria alexandrina against infection with Schistosoma mansoni. L. carinatus soft tissues were extracted with methanol and the resulting crude extract was further fractioned with petroleum ether, methylene chloride, and ethyl acetate (EtOAc). The total antioxidant capacity (TAC) and total phenolic content (TPC) of all extracts were determined. Furthermore, the effect of the highest antioxidant extract on hemocytes activity (phagocytosis), antioxidant parameters, and infection rate of B. alexandrina was assessed. The results showed that, EtOAc extract had the highest antioxidant capacity and total phenolic contents. EtOAc extract led to activation of phagocytic process with a significant increase in the phagocytic indexes of hemocytes after 1, 2, and 4 h of exposure. In addition, it increased the levels of total antioxidant capacity, superoxide dismutase, reduced glutathione, and glutathione-s-transferase in B. alexandrina compared to controls. The infection rate of snails was significantly reduced due to EtOAc extract exposure. These results collectively suggest that EtOAc extract from L. carinatus has an antioxidant capacity and immuostimulatory effect for B. alexandrina infectied with S. mansoni. [ABSTRACT FROM AUTHOR]

Wadi Al-Natrun, Egypt is considered an extreme environment, where, salinity and alkalinity are high. It was aimed in this work to explore such an environment for novel actinobacteria producing bioactive compounds. A total of 31 actinobacteria isolated from sediment of Um-Risha Lake at Wadi Al-Natrun were screened for antimicrobial activity against some Gram-positive and Gramnegative bacteria. The most potent isolate was identified based on the phenotypic and phylogenetic analyses using the 16S rRNA gene sequence and compared to those in the publicly available databases. It showed 99% similarity to Streptomyces violaceoruber strain EA169 and was identified as Streptomyces sp. EMSM31. The antimicrobial activity of this strain was assessed and was highly dependent upon the nutrients and conditions used for cultivation. Strain EMSM31 showed a broad spectrum antagonistic activity against both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis) bacteria recording inhibition zones of 22, 18, 19, 19, and 18 mm, respectively. The maximal activity of secondary metabolite (23mm) was achieved in an optimized production medium containing fructose and yeast extract at pH7 on the fifth day of fermentation at 30°C. Moreover, gas chromatography-mass spectrometry (GC--MS) profiles of produced metabolites revealed apparent differences when compared to the public database of existing natural products. Analysis showed the presence of 3- hydroxy dodecanoic acid (19.49%) as a major compound. This study establishes that streptomycetes from extreme environments may be a rich reservoir for the production of biologically active compounds with pharmaceutical potentials. [ABSTRACT FROM AUTHOR]

Molluscs, owing to their filtrate ability, can accumulate metals that may contaminate food, causing a negative impact on the health of the consumers. Thus, the main objective of the present study was to investigate the heavy metal concentrations in one of the widest broad and consumed surf clams Mactra olorina available in the Great Bitter Lake, Egypt. The concentrations of the heavy metals (Pb, Cd, Cu, and Zn) were seasonally evaluated in water, sediment, and the soft flesh of M. olorina. The specimens were monthly collected from the Egyptian Great Bitter Lake near Fayed City (Ismailia Governorate) for one year, from April 2009 to March 2010. Results revealed that, the annual mean concentrations of heavy metals in water were 1.376±0.562, 0.267±0.329, 2.256±2.909 and 3.355±2.731 μg/l for Pb, Cd, Cu and Zn, respectively. The corresponding concentration values in the sediment were 0.398±0.355, 0.307±0.244, 1.753±0.464 and 8.643±1.821 for Pb, Cd, Cu and Zn μg/g, respectively. While, the annual mean concentrations of heavy metals in soft tissues were 0.538±1.130, 0.262±0.283, 5.395±3.115 and 13.043±5.743 for Pb, Cd, Cu, and Zn μg/g, respectively. Interestingly, heavy metals deposited in the tissues of M. olorina and their environment (water and sediments) recorded a close relationship (0.05 ≥ p ≤0.01) in the current research. In conclusion, though no apparent risk was detected on bivalve consumers from being exposed to a single metal, yet there is a risk from being exposed to the 4 studied metals combined together, especially for high bivalve-consuming groups such as fishermen. Furthermore, environmental parameters need to consider when to use bivalves as indicators of heavy metal pollution since seasonality could affect the absorption of heavy metals. [ABSTRACT FROM AUTHOR]

In aquatic ecosystem biomonitoring, the use of biota and their habitat provides a good indication of conditions and potential threats to any water body. The potential for heavy metal poisoning in humans because of consuming tainted fish has gotten a lot of press around the world. Heavy metal pollutants in water are mostly caused by human activities such as waste disposal, organic fuel combustion, phosphate fertilizers, plastics, and pesticides. The aim of this study was to see how much heavy metals contamination there was in Nile tilapia Oreochromis niloticus and how physicochemical characteristics affected the biomarkers. Heavy metals accumulation (cadmium, lead, zinc, copper, and iron) was studied on the serological indices of a freshwater fish O. niloticus. Fish, water, and sediments were collected at three locations along the Nile River. The findings of this study showed a significant difference in water quality indices in response to pollution levels among the sites studied. Consequently, the current results confirm that the distribution of heavy metals in tissues could potentially deteriorate biochemical parameters of O. niloticus. [ABSTRACT FROM AUTHOR]

The Red Sea is known by its unique coral reef topography that harbors many marine species making the Red Sea a biodiversity hot spot. The molluscan fauna of the Red Sea has been extensively studied for its ecology, biology and economic importance. In the present study, numerous live specimens and gastropod shells were collected from Ain El-Sokhna area on the western shore of the Red Sea's Gulf of Suez. Samplings were done during June-October, 2020. The collected species were identified based on published keys for the identification of Red Sea molluscs. A total of 24 gastropod species belonging to 12 families were identified. Among these, the highest abundant species was Thais savignyi (Muricidae) followed by Cellana rota (Nacellidea). Some other species were rarely abundant such as Conomurex fasciatus (Strombidae), the reef eating snail, Drupella cornus (Muricidae), Nassarius fenistratus, N. castus (Nassariidae), and Polinices pecelephanti (Naticidae). The present findings demonstrate a high molluscan biodiversity at Ain El-Sokhna region of the Red Sea and set the platform for further studies and assessments of biological and biomedical importance of identified molluscs species either as intermediate hosts for parasites or sources for bioactive compounds. [ABSTRACT FROM AUTHOR]