Effects of mancozeb on the testicular histology of the zebrafish (Danio rerio)

Reproduction is a critical and sensitive process for population continuity of the externally fertilizing aquatic organisms. Environmental pollution may adversely effect the reproductive activities of fish. Pesticides are the mobile chemicals that are known to pollute the aquatic ecosystems. Mancozeb is an ethylene-bis-dithiocarbamate (EBDC) fungicide that is frequently used to protect fruits, vegetables, vineyards and field crops against a wide range of fungal diseases. The aim of the current work was to evaluate the acute toxic effects of mancozeb on the testis tissues of zebrafish (Danio rerio). Zebrafish were exposed to 5 ppm and 7.5 ppm of mancozeb concentrations for five days. Testis tissues were removed and fixed in 10% neutral buffered formalin solution. Specimens were embedded in paraffin and 5 μm serial sections were stained with hematoxylin and eosin. The control and the experimental samples were investigated by light microscopy and histopathological changes were evaluated. Mancozeb gave rise to degenerative spermatogenic cells, seminiferous tubule disorganizations, fibrosis, hemorrhage, vacuolization, hypertrophy of spermatocytes, edema, decreased spermatogenic cell clusters and sperms, pyknotic and karyolytic nuclei. These results showed that mancozeb could interrupt the reproductive activity and decrease the fertilization ratio of zebrafish.

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Influences of nanoparticles on aquatic organisms: Current situation of nanoparticles effects in aquatic ecosystems

Sustainable Engineering and Innovation, ISSN 2712-0562 ◽

10.37868/sei.v3i1.id136 ◽

2021 ◽

Vol 3 (1) ◽

pp. 54-60

Author(s):

Didem Gökçe

Keyword(s):

Aquatic Ecosystems ◽

Aquatic Organisms ◽

High Reactivity ◽

Freshwater Ecosystems ◽

Engineered Nanoparticles ◽

Adverse Impacts ◽

Wide Range ◽

Mean Size ◽

Level Of Aggregation ◽

Physical And Chemical

The quick improvement of nanotechnology permits a wide range of utilization of engineered nanoparticles, such as personal care products, medicals, optics, electronics, and automobiles. The nanoparticles manufactured from Ag, Au carbon-nanotube, ZnO, SiO2, TiO2, Cu, Ni, and magnetic ferrites are among the generally utilized in products. The nanoparticles are produced and utilized in large quantities and release into marine and freshwater ecosystems during production, use, discharge, treatment, and deposition. Those particles with a mean size of 1 nm - 100 nm are of potential environmental risks because of their particular qualifications and high reactivity although their great economical values. Based on the studies, the size, shape, and surface physical and chemical characteristics of the nanoparticles show the level of aggregation, solubility, structural and chemical composition, the importance of the use of nanoparticles, and their toxicity with biological systems. Nanoparticles can potentially cause adverse impacts on tissue, cellular, genetic materials, and protein- enzyme levels due to their unique physical and chemical qualifications. In this study, the effects of nanoparticles on aquatic organisms and aquatic ecosystems were evaluated.

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What Do We Know About Toxigenic, Bloom-Forming Cyanobacteria at the Beginning of The 21st Century?

Environmental Analysis & Ecology Studies ◽

10.31031/eaes.2018.02.000529 ◽

2018 ◽

Vol 2 (1) ◽

Author(s):

Magdalena Toporowska

Keyword(s):

Aquatic Ecosystems ◽

Climate Changes ◽

Aquatic Organisms ◽

Biologically Active ◽

Cyanobacterial Blooms ◽

Brackish Waters ◽

Human Health Risks ◽

Cyanobacterial Species ◽

Wide Range ◽

Review Reports

Cyanobacteria are microscopic, prokaryotic organisms capable of mass development in aquatic ecosystems. Cyanobacterial blooms, observed often in various fresh and brackish waters, are growing global problem due to the eutrophication process and climate changes. Different cyanobacterial species may produce wide range of various biologically active secondary metabolites, which may be harmful to aquatic organisms, animals and humans. Microcystins (MCs) are the most known and frequently studied cyanobacterial compounds classified to cyanotoxins. But cyanobacteria are producers of several hundred of other toxins (e.g. nodularins, cylindrospermopsins, anatoxins, saxitoxins), and potentially harmful substances (e.g. oligopeptides other than MCs). In this paper, the present knowledge about cyanobacterial blooms, toxins and other metabolites is shown concisely with references to the latest review reports broadly describing the issues discussed. Human health risks caused by cyanobacteria is also presented

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Viruses in aquatic ecosystems: important advancements of the last 20 years and prospects for the future in the field of microbial oceanography and limnology

Advances in Oceanography and Limnology ◽

10.4081/aiol.2010.5297 ◽

2010 ◽

Vol 1 (1) ◽

pp. 97 ◽

Cited By ~ 37

Author(s):

Stéphan Jacquet ◽

Takeshi Miki ◽

Rachel Noble ◽

Peter Peduzzi ◽

Steven Wilhelm

Keyword(s):

Aquatic Ecosystems ◽

Population Control ◽

Aquatic Organisms ◽

Aquatic Systems ◽

Small Scale ◽

Sequence Information ◽

Viral Ecology ◽

Wide Range ◽

Near Term ◽

Transformation Of Organic Matter

Over the last two decades, viruses in aquatic systems have been observed to modify, influence and control aquatic systems. Since the determination decades ago that viruses were abundant in aquatic ecosystems, researchers have demonstrated that viruses are pervasive and dynamic across the expanse and depth of all aquatic systems as well as at the water-sediment interface. There have been a wide range of methodological advancements during this time. To date, aquatic viruses have been suggested to play vital roles in global and small-scale biogeochemical cycling, community structure, algal bloom termination, gene transfer, and evolution of aquatic organisms. Even in harsh and difficult to study environments, aquatic and benthic viruses have been demonstrated to be major players in carbon cycling and recycling of nutrients from organic material. Taxonomic and metagenomic research has shown us that there are major globally-distributed groups, but that their genomes are filled with sequence information that has no similarity to sequences in existing bioinformatic databases. And while the field of viral ecology has expanded exponentially since the late 1980s, there is much that we do not yet understand about virusmediated processes in aquatic systems. Important near-term steps include the combination of advanced metagenomic techniques with studies of function and population control, standardization of methodological approaches to facilitate global data acquisition without concern over methods-based artefacts, understanding of viral life strategies and their triggers, and the role of viruses in the transformation of organic matter. The purpose of this manuscript is to bring the reader a review of the recent advances in aquatic viral ecology in light of new areas of research, applications of viral ecology to real-world problems, and refinement of models of viral interactions on a range of scales.

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Changes in the Male Reproductive Organs of the Dugong, Dugong dugon (Sirenia: Dugondidae) with Age and Reproductive Activity

Australian Journal of Zoology ◽

10.1071/zo9840721 ◽

1984 ◽

Vol 32 (6) ◽

pp. 721 ◽

Cited By ~ 28

Author(s):

H Marsh ◽

GE Heinsohn ◽

TD Glover

Keyword(s):

Reproductive Tract ◽

Prostate Gland ◽

Reproductive Activity ◽

Reproductive Organs ◽

Seminal Vesicles ◽

Growth Layer ◽

Male Reproductive Tract ◽

Qualitative And Quantitative ◽

Quantitative Examination ◽

Testicular Histology

The anatomy and histology of the male reproductive tract of the dugong (Dugong dugon) is described. Each testis and its adjacent epididymis lie immediately caudal to the corresponding kidney. The seminal vesicles are large but there is no discrete prostate gland and the bulbo-urethral glands are also diffuse. Both qualitative and quantitative examination of the testes and epididymides of 59 males whose ages have been estimated from tusk dentinal growth layer counts indicate that the male dugong does not produce spermatozoa continuously, despite the absence of a distinct breeding season. Individual dugongs were observed with testes at all stages between complete quiescence and full spermatogenesis, and only 10 of the 40 mature males had fully spermatogenic testes and epididymides packed with spermatozoa. Androgenic and spermatogenic activity of the testes appeared to be in phase, but the testicular histology of some old males suggested that they may have been sterile for long periods.

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Toxic or Not Toxic, That Is the Carbon Quantum Dot’s Question: A Comprehensive Evaluation with Zebrafish Embryo, Eleutheroembryo, and Adult Models

Polymers ◽

10.3390/polym13101598 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1598

Author(s):

Chih-Yu Chung ◽

Yu-Ju Chen ◽

Chia-Hui Kang ◽

Hung-Yun Lin ◽

Chih-Ching Huang ◽

...

Keyword(s):

Zebrafish Embryo ◽

Comprehensive Evaluation ◽

Aquatic Organisms ◽

Carbon Quantum Dots ◽

Adult Zebrafish ◽

Fish Embryo ◽

Wide Range ◽

Different Types ◽

Low Toxicity

Carbon quantum dots (CQDs) are emerging novel nanomaterials with a wide range of applications and high biocompatibility. However, there is a lack of in-depth research on whether CQDs can cause acute or long-term adverse reactions in aquatic organisms. In this study, two different types of CQDs prepared by ammonia citrate and spermidine, namely CQDAC and CQDSpd, were used to evaluate their biocompatibilities. In the fish embryo acute toxicity test (FET), the LD50 of CQDAC and CQDSpd was about 500 and 100 ppm. During the stage of eleutheroembryo, the LD50 decreased to 340 and 55 ppm, respectively. However, both CQDs were quickly eliminated from embryo and eleutheroembryo, indicating a lack of bioaccumulation. Long-term accumulation of CQDs was also performed in this study, and adult zebrafish showed no adverse effects in 12 weeks. In addition, there was no difference in the hatchability and deformity rates of offspring produced by adult zebrafish, regardless of whether they were fed CQDs or not. The results showed that both CQDAC and CQDSpd have low toxicity and bioaccumulation to zebrafish. Moreover, the toxicity assay developed in this study provides a comprehensive platform to assess the impacts of CQDs on aquatic organisms in the future.

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The Role of Aquatic Ecosystems (River Tua, Portugal) as Reservoirs of Multidrug-Resistant Aeromonas spp.

Water ◽

10.3390/w13050698 ◽

2021 ◽

Vol 13 (5) ◽

pp. 698

Author(s):

Sónia Gomes ◽

Conceição Fernandes ◽

Sandra Monteiro ◽

Edna Cabecinha ◽

Amílcar Teixeira ◽

...

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Nalidixic Acid ◽

Water Samples ◽

Aquatic Ecosystems ◽

Anthropogenic Activities ◽

Aquatic Organisms ◽

Resistant Bacteria ◽

Anthropogenic Pressures ◽

Resistance Rates

The inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas spp., taken as representative of the autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin). The prevalence and degree of antibiotic resistance was examined using motile aeromonads as a potential indicator of antimicrobial susceptibility for the aquatic environment. Water samples were collected from the middle sector of the river, which is most impacted area by several anthropogenic pressures. Water samples were plated on an Aeromonas-selective agar, with and without antibiotics. The activity of 19 antibiotics was studied against 30 isolates of Aeromonas spp. using the standard agar dilution susceptibility test. Antibiotic resistance rates were fosfomycin (FOS) 83.33%, nalidixic acid (NA) 60%, cefotaxime (CTX) 40%, gentamicin (CN) 26.67%, tobramycin (TOB) 26.67%, cotrimoxazole (SXT) 26.67%, chloramphenicol (C) 16.67%, and tetracycline (TE) 13.33%. Some of the nalidixic acid-resistant strains were susceptible to fluoroquinolones. Multiple resistance was also observed (83.33%). The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying antimicrobial resistance (AMR) in aquatic ecosystems. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance because anthropogenic activities frequently impact them. The potential risk of multi- and pan-resistant bacteria transmission between animals and humans should be considered in a “One Health—One World” concept.

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Applications of Coupled Fixed Points for Multivalued Maps in the Equilibrium in Duopoly Markets and in Aquatic Ecosystems

Axioms ◽

10.3390/axioms10020044 ◽

2021 ◽

Vol 10 (2) ◽

pp. 44

Author(s):

Gana Gecheva ◽

Miroslav Hristov ◽

Diana Nedelcheva ◽

Margarita Ruseva ◽

Boyan Zlatanov

Keyword(s):

Fixed Points ◽

Aquatic Ecosystems ◽

Market Equilibrium ◽

Multivalued Maps ◽

New Class ◽

Wide Range ◽

Coupled Fixed Points ◽

Ordered Pairs ◽

Duopoly Markets

We have obtained a new class of ordered pairs of multivalued maps that have pairs of coupled fixed points. We illustrate the main result with two examples that cover a wide range of models. We apply the main result in models in duopoly markets to get a market equilibrium and in aquatic ecosystems, also to get an equilibrium.

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Toxicity investigation of CeO2 nanoparticles coated with glucose and exopolysaccharides levan and pullulan on the bacterium Vibrio fischeri and aquatic organisms Daphnia magna and Danio rerio

Aquatic Toxicology ◽

10.1016/j.aquatox.2021.105867 ◽

2021 ◽

pp. 105867

Author(s):

Ivana Milenković ◽

Ksenija Radotić ◽

Jovana Despotović ◽

Branka Lončarević ◽

Marija Lješević ◽

...

Keyword(s):

Daphnia Magna ◽

Danio Rerio ◽

Vibrio Fischeri ◽

Aquatic Organisms ◽

Ceo2 Nanoparticles

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Sustainable Sources from Aquatic Organisms for Cosmeceuticals Ingredients

Cosmetics ◽

10.3390/cosmetics8020048 ◽

2021 ◽

Vol 8 (2) ◽

pp. 48

Author(s):

Carmen G. Sotelo ◽

María Blanco ◽

Patricia Ramos ◽

José A. Vázquez ◽

Ricardo I. Perez-Martin

Keyword(s):

Social Issues ◽

Good Condition ◽

Aquatic Organisms ◽

The Body ◽

Fishing Activity ◽

Marine Biomass ◽

Cosmetic Industry ◽

Wide Range ◽

Long Life ◽

By Products

Long life expectancy of populations in the developing world together with some cultural and social issues has driven the need to pay special attention to health and physical appearance. Cosmeceuticals are gaining interest in the cosmetic industry as their uses fulfills a double purpose: the requirements of a cosmetic (clean, perfume, protect, change the appearance of the external parts of the body or keeping them in good condition) with a particular bioactivity function. The cosmetics industry, producing both cosmetics and cosmeceuticals, is currently facing numerous challenges to satisfy different attitudes of consumers (vegetarianism, veganism, cultural or religious concerns, health or safety reasons, eco-friendly process, etc.). A currently growing trend in the market is the interest in products of low environmental impact. Marine origin ingredients are increasingly being incorporated into cosmeceutical preparations because they are able to address several consumer requirements and also due to the wide range of bioactivities they present (antioxidant, whitening, anti-aging, etc.). Many companies claim “Marine” as a distinctive marketing signal; however, only a few indicate whether they use sustainable ingredient sources. Sustainable marine ingredients might be obtained using wild marine biomass through a sustainable extractive fishing activity; by adopting valorization strategies including the use of fish discards and fish by-products; and by sustainably farming and culturing marine organisms.

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