In this overview (introductory article to a special issue including 14 papers), we consider all main types of natural and artificial inland freshwater habitas (fwh). For each type, we identify the main biodiversity patterns and ecological features, human impacts on the system and environmental issues, and discuss ways to use this information to improve stewardship. Examples of selected key biodiversity/ecological features (habitat type): narrow endemics, sensitive (groundwater and GDEs); crenobionts, LIHRes (springs); unidirectional flow, nutrient spiraling (streams); naturally turbid, floodplains, large-bodied species (large rivers); depth-variation in benthic communities (lakes); endemism and diversity (ancient lakes); threatened, sensitive species (oxbow lakes, SWE); diverse, reduced littoral (reservoirs); cold-adapted species (Boreal and Arctic fwh); endemism, depauperate (Antarctic fwh); flood pulse, intermittent wetlands, biggest river basins (tropical fwh); variable hydrologic regime—periods of drying, flash floods (arid-climate fwh). Selected impacts: eutrophication and other pollution, hydrologic modifications, overexploitation, habitat destruction, invasive species, salinization. Climate change is a threat multiplier, and it is important to quantify resistance, resilience, and recovery to assess the strategic role of the different types of freshwater ecosystems and their value for biodiversity conservation. Effective conservation solutions are dependent on an understanding of connectivity between different freshwater ecosystems (including related terrestrial, coastal and marine systems).

M YCOSES and plant fungal pathogens are limiting factors highly affecting public health and crop production. Some fungal strains have been documented to be resistant to the commonly used drugs. Therefore, finding out new and pivotal antifungal drugs is becoming a global priority. Herein, we evaluated the in vitro antifungal activities of different crude polar (methanol and ethyl acetate) and non-polar (chloroform and petroleum ether) extracts of the mostly untapped brown seaweed Hormophysa cuneiformis (order Fucales, Phaeophyceae), in the Egyptian coastal waters, against eight pathogenic fungi: Aspergillus flavus, A. fumigatus, Candida albicans and Trichosporonas ahii (as human pathogens), and Alternaria alternata, Cladosporium herbarum, Fusarium oxysporum and Penicillium digitatum (as plant pathogens). The agar well diffusion assay was applied. Our findings showed that the chloroform extract only exhibited a potential antifungal activity against all tested fungal isolates, particularly T. asahii, C. albicans, A. fumigatus and C. herbarum, while the other extracts had relatively no remarkable effects. The minimum inhibitory concentrations (MICs) ranged between 0.78 and 6.25µg.ml-1 and these values are very close to those of the standard antifungal drug amphotericin B (0.63-5µg.ml-1). GC-MS analysis of the crude chloroform extract revealed 45 different bioactive compounds, mainly including 18 different species of saturated, monounsaturated and polyunsaturated fatty acids (71.48%) and some essential oils. The major constituents were arachidonic (C20:4

Although a broad variety of classes of bioactive compounds have already been isolated from seaweeds of the genus Dictyota, most different species are still chemically and biologically unexplored. Dictyota species are well-known brown seaweeds belonging to the Dictyotaceae (Phaeophyta). The phytochemical composition within the genus Dictyota has recently received considerable interest, and a vast array of components, including diterpenes, sesquiterepenes, sterols, amino acids, as well as saturated and polyunsaturated fatty acids, have been characterized. The contribution of these valued metabolites to the biological potential, which includes anti-proliferative, anti-microbial, antiviral, antioxidant, anti-inflammatory, and anti-hyperpigmentation activities, of the genus Dictyota has also been explored. Therefore, this is the most comprehensive review, focusing on the published literature relevant to the chemically and pharmacologically diverse biopharmaceuticals isolated from different species of the genus Dictyota during the period from 1976 to now.

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