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See detailImpact of three phtalate esters on the sexual reproduction of the Monogont rotifer, Brachionus calyciflorus
Cruciani, Valentina ULg; Iovine, Catherine; Thomé, Jean-Pierre ULg et al

in Ecotoxicology (2016), 25(1), 192-200

Phthalate esters are widespread contaminants that can cause endocrine disruption in vertebrates. Studies showed that molecules with hormonal activities in vertebrates and invertebrates can affect asexual ... [more ▼]

Phthalate esters are widespread contaminants that can cause endocrine disruption in vertebrates. Studies showed that molecules with hormonal activities in vertebrates and invertebrates can affect asexual and sexual reproduction in rotifers. We investigated the impact of di-hexylethyl phthalate (DEHP), di-butyl phthalate (DBP) and butylbenzyl phthalate (BBP), on the asexual and sexual reproduction of the freshwater monogonont rotifer Brachionus calyciflorus in order to determine a potential environmental risk for sexual reproduction. We observed that DEHP has no significant impact on both asexual and sexual reproduction up to 2 mg/L. DBP has a positive effect on asexual reproduction at concentrations from 0.05 to 1mg/L, but depresses it at 2 mg/L. Sexual reproduction is only affected with 2mg/L and the impact observed is negative. BBP displayed a negative impact on both asexual and sexual reproduction at 1 and 2 mg/L. However we showed that the impacts of BBP on fertilization rates observed are due to the decrease in population growth rates at these concentrations and are not due to a direct impact of BBP on the fertilization process. Similar conclusions are likely applicable to the impacts on mixis and production of cysts as well. Our results show that sexual reproduction in B. calyciflorus is not more sensitive than asexual reproduction to any of the substances tested which indicates the mode of action of these molecules is related to general toxicity, not to an interference with potential endocrine regulation of sexual reproduction. Comparison of effect concentrations and surface water contamination by phthalate esters suggests these compounds do not constitute a risk for these environments. [less ▲]

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See detailToxicokinetics of selenium in the slider turtle Trachemys scripta
Dyc, Christelle; Far, Johann ULg; Gandar, Frederic ULg et al

in Ecotoxicology (2016), 25

Selenium (Se) is an essential element that can be harmful for wildlife. However, its toxicity in poikilothermic amniotes, including turtles, remains poorly investigated. The present study aims at ... [more ▼]

Selenium (Se) is an essential element that can be harmful for wildlife. However, its toxicity in poikilothermic amniotes, including turtles, remains poorly investigated. The present study aims at identifying selenium toxicokinetics and toxicity in juvenile slider turtles (age: 7 months), Trachemys scripta, dietary exposed to selenium, as selenomethionine SeMet, for eight weeks. Non-destructive tissues (i.e. carapace, scutes, skin and blood) were further tested for their suitability to predict selenium levels in target tissues (i.e. kidney, liver and muscle) From conservation perspective. 130 juvenile yellow-bellied slider turtles were assigned in three groups of 42 individuals each (i.e. control, SeMet1 and SeMet2). These groups were subjected to a feeding trial including an eight-week supplementation period SP8 and a following four-week elimination period EP4. During the SP8, turtles fed on diet containing 1.1 ± 0.04, 22.1 ± 1.0 and 45.0 ± 2.0 µg.g-1 of selenium (control, SeMet1 and SeMet2, respectively). During the EP4, turtles fed on non-supplemented diet. At different time during the trial, six individuals per group were sacrificed and tissues collected (i.e. carapace, scutes, skin, blood, liver, kidney, muscle) for analyses. During the SP8 (Figure 1), both SeMet1 and SeMet2 turtles efficiently accumulated selenium from a SeMet dietary source. The more selenium was concentrated in the food, the more it was in the turtle body but the less it was removed from their tissues. Moreover, SeMet was found to be the more abundant selenium species in turtles’ tissues. Body condition (i.e. growth in mass and size, feeding behaviour and activity) and survival of the SeMet1 and SeMet2 turtles seemed to be unaffected by the selenium exposure. There were clear evidences that reptilian species are differently affected by and sensitive to selenium exposure but the lack of any adverse effects was quite unexpected. [less ▲]

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See detailAcanthocephalan parasites: help or burden in Gammarid amphipods exposed to cadmium?
Gismondi, Eric ULg; Cossu-Leguille, Carole; Beisel, Jean-Nicolas

in Ecotoxicology (2012), 21

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See detailUsing sets of behavioral biomarkers to assess short-term effects of pesticide: a study case with endosulfan on frog tadpoles
Denoël, Mathieu ULg; D'hooghe, Bastien; Ficetola, G. Francesco et al

in Ecotoxicology (2012), 21(4), 1240-1250

Pesticides and other chemicals often have detrimental effects at environmental concentrations. Many amphibian species are particularly threatened because of their susceptibility but also because wetlands ... [more ▼]

Pesticides and other chemicals often have detrimental effects at environmental concentrations. Many amphibian species are particularly threatened because of their susceptibility but also because wetlands are often polluted. Behavioral assessments of toxicity have the advantage of showing sublethal effects but quantitative measures at varied scales of integrations are rarely considered together. In this study, we aimed at showing that these behavioral endpoints could be differently affected across time and concentrations, and be biomarkers of toxicity. To this end, we tested the effects of an organochlorine pesticide (endosulfan) on amphibians during a standard 96 h test. We evaluated possible lag effects in continuing the analyses after removal of the pesticide. The study was based on 240 tadpoles (4 pesticide treatments: 0.4, 3, 22, and 282 lg/l, 1 control and 1 solvent-control). Abnormal behaviors such as lying and swirling rapidly were exhibited only in the presence of the pesticide. Essential functions such as breathing and feeding were deeply affected by the pesticide: contaminated tadpoles breathed and fed less than control tadpoles. They also moved less and occupied a more central position in the aquariums in the presence of the pesticide. A higher mortality was only found at the highest concentration. These results suggest that endosulfan is toxic to amphibians at environmental concentrations. Behavioral markers showed potential as early warning systems. They should thus be used in complement to other markers to detect sublethal effects only a few days after application of the pesticide and at concentrations where mortality does not occur. [less ▲]

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See detailCadmium toxicokinetics and bioaccumulation in turtles: trophic exposure of Trachemys scripta elegans
Guirlet, Elodie; Das, Krishna ULg

in Ecotoxicology (2012), 1

Ecotoxicological data in reptiles are mainly represented by field studies reporting tissues burden of wild-captured individuals but much less is known on processes of uptake, depuration, accumulation and ... [more ▼]

Ecotoxicological data in reptiles are mainly represented by field studies reporting tissues burden of wild-captured individuals but much less is known on processes of uptake, depuration, accumulation and effects of inorganic contaminants in these species. In this study, females’ Trachemys scripta elegans were exposed to cadmium (Cd) through a CdCl2 supplemented-diet with increased environmental relevant concentrations during 13 weeks and then went through a decontamination phase during 3 weeks being fed uncontaminated food. Blood and feces were collected during the three phases of the experiment and the turtles were sacrificed at the end of the experiment and organs samples collected. The Cd concentrations in blood remained stable over the course of the experiment while Cd concentrations in feces increased with time and with amount of Cd ingested. Assimilation efficiency in liver and kidney together was low (0.7 – 6.1 %) but did occur and Cd accumulated in a dose-dependent manner in organs in the following order of concentrations: kidney>liver>pancreas>muscle. In terms of organs burden, Cd-burden was the highest in liver followed by kidney and pancreas. The assimilation efficiency decreased as Cd ingested increased suggesting that at higher dose of Cd absorption decreased and/or depuration increased. Mineral content of the liver was modified according to Cd level with increased concentrations of zinc and iron with increasing Cd levels. Accumulation of Cd had no effects on survival, food consumption, growth or weight and length suggesting no effect of treatment on females’ body conditions. [less ▲]

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See detailIntra-specific variation in nitrate tolerance in tadpoles of the Natterjack toad.
Miaud, C.; Oromi Farrús, Neus ULg; Guerrero, S. et al

in Ecotoxicology (2011), 20

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