Schistosoma mansoni:interference with cercarial host-finding by various aquatic organisms

1979 ◽  
Vol 53 (1) ◽  
pp. 7-14 ◽  
Author(s):  
N. Ø. Christensen
Keyword(s):  
Lemna Minor ◽  
Daphnia Pulex ◽  
Aquatic Organisms ◽  
Botryococcus Braunii ◽  
Bufo Bufo ◽  
Host Finding ◽  
Ceratophyllum Demersum ◽  
Predatory Behaviour ◽  
Aquatic Vertebrates ◽  
Lebistes Reticulatus

ABSTRACTSchistosoma mansonicercariae labelled with75Se-methionine were used to study host-finding capacity by determining the radioactivity of exposed mouse “target” tails. Possible interfering effects of some aquatic vertebrates and invertebrates, plants and algae and secretions and excretions of aquatic organisms were examined.A marked interferent effect due to predatory behaviour was produced byCyclops strenuus(Copepoda),Daphnia pulexandD. longispina(Cladocera),Notodromas monachaandCypria ophthalmica(Ostracoda) andLebistes reticulatus(guppy).Bufo bufo(Amphibia) andPlanaria lugubris(Turbellaria) interfered significantly, presumably by secreting cercaricidal toxins. Several other organisms apparently produced no interference. The interferent effect of the plant speciesCeratophyllum demersum, Elodea canadensis, Lemna minor, Ranunculus aquaticus, Holcus lanatus(grass) andBotryococcus brauniiwas particularly pronounced when they were confined to the surface layer of the water. Several other species did not interfere with host-finding.

Interference with Fasciola hepatica snail finding by various aquatic organisms

Parasitology ◽  
1977 ◽  
Vol 74 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Niels Ørnbjerg Christensen ◽  
Peter Nansen ◽  
Flemming Frandsen
Keyword(s):  
Fasciola Hepatica ◽  
Daphnia Pulex ◽  
Aquatic Organisms ◽  
Host Finding ◽  
Host Snail ◽  
Predatory Behaviour ◽  
Lymnaea Truncatula

Previous studies using radioactive miracidia have shown that a number of non-host snails and bivalves, interposed as ‘decoys’ in linear test channels, may interfere with the capacity of Fasciola hepatica miracidia to infect Lymnaea truncatula. Applying similar experimental principles, the role of several other potential interferents have been analysed in the present study. Daphnia pulex (Cladocera) and larvae of Corethra sp. (Diptera) exercised significant interfering effects by protecting ‘target’ snails from infection. Evidence suggested that this effect was a result of their normal predatory behaviour. Other organisms including Herpobdella testacea and Helobdella stagnalis (Hirudinea), Acellus aquaticus (Isopoda), Planaria lugubris (Turbellaria) and L. Truncatula egg clusters failed to interfere with miracidial host-finding. Nor did P. lugubris and L. truncatula ‘conditioned water’ interfere with the capacity of the miracidia to infect their host snail.

scholarly journals Acute toxicity of maneb in the tadpoles of common and green toad / Akutna toksičnost maneba u punoglavaca smeđe i zelene krastače

2015 ◽  
Vol 66 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Mert Gürkan ◽  
Sibel Hayretdağ
Keyword(s):  
Fruits And Vegetables ◽  
Aquatic Organisms ◽  
Bufo Bufo ◽  
Development Stage ◽  
Future Research ◽  
Liver Necrosis ◽  
Adverse Conditions ◽  
Green Toad ◽  
Aquatic Vertebrates ◽  
The Common

Abstract Pesticides used in agriculture can have hazardous effects on aquatic organisms, and amphibians are even more threatened than other aquatic vertebrates. Maneb is widely used to control fungal diseases on crops, fruits, and vegetables. The aim of this study was to investigate the acute toxic effects of maneb on the common (Bufo bufo) and green toad (Pseudepidalea viridis) tadpoles. Tadpoles at the development stage 21 were exposed to maneb (0-5 mg L-1) for 120 h. Maneb LC50 values at hour 120 were 1.966 mg L-1 for B. bufo and 0.332 mg L-1 for P. viridis. To the best of our knowledge, these are the first published LC50 findings for the two species. Visceral oedema and tail deformations were observed in both species. We also observed liver necrosis, pronephric tubule deformations, somite deteriorations, and visceral oedema at maneb concentrations ≥0.1 mg L-1 for B. bufo and ≥0.05 mg L-1 for P. viridis. Our results show that B. bufo tadpoles have a much higher resilience to maneb than P. viridis tadpoles. This resilience seems to be related to the larger size of the B. bufo tadpoles and their ability to metamorphose faster in adverse conditions. Future research should look into the mechanisms of toxic action of maneb in anurans.

scholarly journals Degradation Studies of Selected Bisphenols in the Presence of β-Cyclodextrin and/or Duckweed Water Plant

2020 ◽  
Vol 103 (2) ◽  
pp. 439-448
Author(s):  
Aleksandra Kaleniecka ◽  
Paweł K Zarzycki
Keyword(s):  
Green Chemistry ◽  
Lemna Minor ◽  
Aquatic Organisms ◽  
Treated Wastewater ◽  
Biological Research ◽  
Data Set ◽  
Active Biomass ◽  
Treatment Processes ◽  
Water Plant ◽  
Interesting Alternative

Abstract Background: This research reports a multivariate experiment enabling observation of the potential application of macrocyclic compound [β-cyclodextrin (β-CD)] and/or duckweed organisms as the active factors for elimination of selected bisphenols A, B, and S from water samples. Objective: Target bisphenols selection was based on observation that such components can be present in food or environmental samples (e.g., vegetable/fruit juices, milk, drinking water, or treated wastewater). Methods: Biological research was carried out using aquatic organisms containing chlorophyll, particularly duckweed (Lemna minor L), that may work as an active biomass for the elimination or extraction of bisphenols micropollutants from water. Using such a system, we studied the potential encapsulation effect and removal efficiency of nontoxic macrocyclic oligosaccharide (β-cyclodextrin) acting as an encapsulation reagent to promote the removal of selected bisphenols from liquid phase both with and without the presence of duckweed biomass. Results: Experimental data have revealed that β-CD or combined β-CD/duckweed system has an effect on bisphenols elimination from water. The initial data set obtained from this preliminary experiment (and combined with supramolecular complex formation data calculated from chromatographic experiments, published previously) enables designing of further experiments focusing on the development of green chemistry technology. Conclusions: It is hoped that this may be used for the efficient removal of low-molecular-mass micropollutants using classical technological wastewater treatment processes modified by biomass and macrocyclic additives. This process needs to be optimized, but the results presented have revealed that such green chemistry technology, if successful, may be an interesting alternative for the selective removal of the micropollutants investigated from wastewater using classical adsorbents (e.g., carbons and carbon-related nanomaterials), particularly in terms of the worldwide problem with microplastic pollutants in the environment and food products.

scholarly journals Stoichiometric controls of mercury dilution by growth

2007 ◽  
Vol 104 (18) ◽  
pp. 7477-7482 ◽  
Author(s):  
Roxanne Karimi ◽  
Celia Y. Chen ◽  
Paul C. Pickhardt ◽  
Nicholas S. Fisher ◽  
Carol L. Folt
Keyword(s):  
Steady State ◽  
Rapid Growth ◽  
Daphnia Pulex ◽  
Somatic Growth ◽  
Aquatic Organisms ◽  
High Quality ◽  
Nutrient Quality ◽  
Ingestion Rates ◽  
Biokinetic Model ◽  
Ankistrodesmus Falcatus

Rapid growth could significantly reduce methylmercury (MeHg) concentrations in aquatic organisms by causing a greater than proportional gain in biomass relative to MeHg (somatic growth dilution). We hypothesized that rapid growth from the consumption of high-quality algae, defined by algal nutrient stoichiometry, reduces MeHg concentrations in zooplankton, a major source of MeHg for lake fish. Using a MeHg radiotracer, we measured changes in MeHg concentrations, growth and ingestion rates in juvenile Daphnia pulex fed either high (C:P = 139) or low-quality (C:P = 1317) algae (Ankistrodesmus falcatus) for 5 d. We estimated Daphnia steady-state MeHg concentrations, using a biokinetic model parameterized with experimental rates. Daphnia MeHg assimilation efficiencies (≈95%) and release rates (0.04 d−1) were unaffected by algal nutrient quality. However, Daphnia growth rate was 3.5 times greater when fed high-quality algae, resulting in pronounced somatic growth dilution. Steady-state MeHg concentrations in Daphnia that consumed high-quality algae were one-third those of Daphnia that consumed low-quality algae due to higher growth and slightly lower ingestion rates. Our findings show that rapid growth from high-quality food consumption can significantly reduce the accumulation and trophic transfer of MeHg in freshwater food webs.

scholarly journals Specialization directs habitat selection responses to a top predator in semiaquatic but not aquatic taxa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hana Šigutová ◽  
Filip Harabiš ◽  
Martin Šigut ◽  
Jiří Vojar ◽  
Lukáš Choleva ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Vegetation Structure ◽  
Aquatic Organisms ◽  
Bufo Bufo ◽  
Freshwater Ecosystems ◽  
Similar Response ◽  
Top Predator ◽  
Generalist Species ◽  
Selection Responses ◽  
Floating Macrophytes

AbstractHabitat selectivity has become an increasingly acknowledged mechanism shaping the structure of freshwater communities; however, most studies have focused on the effect of predators and competitors, neglecting habitat complexity and specialization. In this study, we examined the habitat selection of semiaquatic (amphibians: Bufonidae; odonates: Libellulidae) and aquatic organisms (true bugs: Notonectidae; diving beetles: Dytiscidae). From each family, we selected one habitat generalist species able to coexist with fish (Bufo bufo, Sympetrum sanguineum, Notonecta glauca, Dytiscus marginalis) and one species specialized in fishless habitats (Bufotes viridis, Sympetrum danae, Notonecta obliqua, Acilius sulcatus). In a mesocosm experiment, we quantified habitat selection decisions in response to the non-consumptive presence of fish (Carassius auratus) and vegetation structure mimicking different successional stages of aquatic habitats (no macrophytes; submerged and floating macrophytes; submerged, floating, and littoral-emergent macrophytes). No congruence between habitat specialists and generalists was observed, but a similar response to fish and vegetation structure defined both semiaquatic and aquatic organisms. While semiaquatic generalists did not distinguish between fish and fishless pools, specialists avoided fish-occupied pools and had a preferred vegetation structure. In aquatic taxa, predator presence affected habitat selection only in combination with vegetation structure, and all species preferred fishless pools with floating and submerged macrophytes. Fish presence triggered avoidance only in the generalist bug N. glauca. Our results highlight the significance of habitat selectivity for structuring freshwater ecosystems and illustrate how habitat selection responses to a top predator are dictated by specialization and life history.

scholarly journals Phytoremediation of Physico-chemical Parameters in Wastewater Effluents from Car Wash Bays in Yenagoa Metropolis, Nigeria

2021 ◽  
Vol 2 (6) ◽  
pp. 20-26
Author(s):  
Odafivwotu Ohwo ◽  
R. Alexander Bekeowei
Keyword(s):  
Lemna Minor ◽  
Pistia Stratiotes ◽  
Ceratophyllum Demersum ◽  
Chemical Parameters ◽  
Retention Period ◽  
Untreated Wastewater ◽  
Physico Chemical ◽  
Car Wash ◽  
Wastewater Samples ◽  
Wastewater Effluents

Surface water pollution through the discharge of untreated wastewater is on the increase globally. Efforts made using conventional techniques had not yielded the needed results. This study was conducted to determine the effectiveness of some native aquatic plants for the removal of some physico–chemical parameters from car wash wastewater effluents in Yenagoa metropolis. The plants used for this study were lemna minor, nymphaea nouchalli, pistia-stratiotes, eichhornia crassipes and ceratophyllum demersum; while the physico-chemical parameters investigated in this study include pH, DO, COD, BOD5, NO3, PO4 and turbidity. The wastewater samples collected from car wash bays were analysed to determine the level of the physico-chemical parameters concentrations using standard methods. The experiment was conducted in a green house for 42 days retention period. The results indicated that the cultured plants reduced the physico-chemical parameters to a minimum level, except DO, which increased in concentration. Therefore, they are considered good bioremediators of the parameters under review and the bioremediation potentials of the plants are in the order of P. stratiotes > L. minor > E. crassipes > N. nouchalli> C. demersum. It is therefore recommended that these plants should be used to treat wastewater effluents based on the investigated physico-chemical parameters.

Toxicity and removal of Direct Red 28 diazo dye in living polymeric systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1628-1635 ◽  
Author(s):  
Andrei Lobiuc ◽  
Stefan Olaru ◽  
Elena Iren Hancu ◽  
Naela Costica ◽  
Maria Emiliana Fortuna ◽  
...  
Keyword(s):  
Congo Red ◽  
Lemna Minor ◽  
Aquatic Organisms ◽  
Significant Inhibition ◽  
Point Of View ◽  
Water Soluble ◽  
Aquatic Environments ◽  
Polymeric Systems ◽  
Red Dye ◽  
Direct Red 28

Aquatic environments are often contaminated with various compounds, with potential toxicity towards aquatic organisms, which may enter the food chain. Azo dyes are used in various industries and contamination of waters has been reported. The present paper assesses the toxicity of the synthetic, water soluble Congo Red dye towards Lemna minor from a physiological and cytogenetical point of view. The dye was tested in 5-5000 ppm concentrations. Total frond surface, root growth and fresh mass reductions were registered from 5 ppm dye concentration, with a concentration-dependent response and calculated EC50 of 1530 ppm. Plant growth was completely inhibited above 2500 ppm. Dye accumulation was observed in tissues, along with necrosis formation. Chlorophyll a contents decreased, while carotenoid contents increased above 2500 ppm. Significant inhibition of PSII efficiency was recorded above 1000 ppm. Mitotic indices were decreased at 5 and 1000 ppm dye and were 0 at 5000 ppm. The number of chromosomal aberrations significantly increased at 5 and 1000 ppm dye. The growth medium was decontaminated up to 56% at 250 ppm dye concentration by Lemna plants. Congo Red azo dye presented toxicity towards Lemna minor, from a physiological and cyotgenetical point of view, especially at higher concentrations. In the same time, a phytoremediation potential of duckweed with respect to the tested dye was demonstrated.

THE EFFECT OF THE ULTRA-VIOLET COMPONENT OF THE SUN'S RADIATION UPON SOME AQUATIC ORGANISMS

1930 ◽  
Vol 2 (5) ◽  
pp. 312-317 ◽  
Author(s):  
A. Brooker Klugh
Keyword(s):  
Prolonged Exposure ◽  
Daphnia Pulex ◽  
Solar Spectrum ◽  
Ultra Violet ◽  
Aquatic Organisms ◽  
Ultra Violet Radiation ◽  
Point Of Interest ◽  
Comparison Of The Results ◽  
Considerable Depth ◽  
Violet Radiation

Specimens of three species of fresh-water entomostracans—Daphnia pulex, Daphnia magna and Cypris reticulate—were each exposed to sunlight which had passed through filters which transmitted different regions of the solar spectrum. One filter ("Total") transmitted both visible and ultra-violet radiation, a second ("Novial") transmitted the visible only and a third ("U.V.") transmitted only the ultra-violet. By prolonged exposure the animals were killed under the Total and U.V. filters, while under the Novial they lived indefinitely. The chief point of interest lies in the comparison of the results obtained with these entomostracans which live in shallow pools with the results of previous experiments (2) on three marine entomostracans which remain at a considerable depth in the sea when the illumination is at all intense; the comparison shows that the former have a far greater resistance to the lethal effects of the sun's ultraviolet radiation. Developing embryos of the squid, Loligo pealii, were experimented upon in a similar manner; these embryos, which are enclosed in a gelatinous matrix attached to large algae in the intertidal zone, and, at low tide, are exposed to full sunlight, were extremely resistant to ultra-violet radiation.

Changes of toxicological properties of biodegradation products of anthracene and phenanthrene

2000 ◽  
Vol 41 (12) ◽  
pp. 31-38 ◽  
Author(s):  
T. M. Traczewska
Keyword(s):  
Aquatic Ecosystems ◽  
Ames Test ◽  
Lemna Minor ◽  
Trophic Levels ◽  
Selenastrum Capricornutum ◽  
Test Results ◽  
Biological Degradation ◽  
Test Organisms ◽  
Biotransformation Products ◽  
Lebistes Reticulatus

The aim of this work was to determine toxicity and mutagenicity of anthracene and phenanthrene and their microbial biotransformation products. The following representatives of different trophic levels of aquatic biocenoses were selected for the toxicological tests: Selenastrum capricornutum, Lemna minor, Daphnia magna and Lebistes reticulatus. Mutagenic properties were determined by Ames test. Results of the analyses confirmed toxicity of studied PAHs for test organisms. Metabolites produced during biological degradation of anthracene and phenanthrene were also harmful for selected representatives of aquatic ecosystems.

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