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| Coquillé, Nathalie; Morin, Soizic. |
| Diatom teratologies have intrigued scientists since the XIXth century, with respect to their causes and origins. These deformities, mainly observed in long-term cultures or under high levels of pollution, were poorly considered, until they were recently found to be potential indicators of toxic impairment of freshwaters. However, very little is known about their ecology. In this study, the growth and fitness of morphologically distinct descendants of the same cell line of Gomphonema gracile (teratological vs. non teratological forms) were compared over a typical growth cycle. Contrary to expectations, teratological populations grew slightly faster, at a rate of 0.47 ± 0.03 divisions.day−1, versus 0.41 ± 0.04 for the normal morphotype. They had similar... |
| Tipo: Text |
Palavras-chave: Gomphonema gracile; Morphology-based assessment; Teratology; Transmissibility of morphological characters; Phenotypic variability; Fitness. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61326/64913.pdf |
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| Coquille, Nathalie; Menard, Dominique; Rouxel, Julien; Dupraz, Valentin; Eon, Melissa; Pardon, Patrick; Budzinski, Helene; Morin, Soizic; Parlanti, Edith; Stachowski-haberkorn, Sabine. |
| Microalgae, which are the foundation of aquatic food webs, may be the indirect target of herbicides used for agricultural and urban applications. Microalgae also interact with other compounds from their environment, such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This study aimed to evaluate the influence of natural DOM on the toxicity of three herbicides (diuron, irgarol and S-metolachlor), singly and in ternary mixtures, to two marine microalgae, Chaetoceros calcitrans and Tetraselmis suecica, in monospecific, non-axenic cultures. Effects on growth, photosynthetic efficiency (Ф’M) and relative lipid content were evaluated. The chemical environment (herbicide and nutrient concentrations, dissolved organic carbon... |
| Tipo: Text |
Palavras-chave: Microalgae; Herbicides; Natural dissolved organic matter; DOM; Toxicity; Interactions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53964/55113.pdf |
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| Coquille, Nathalie; Jan, Gwilherm; Moreira, Aurelie; Morin, Soizic. |
| Many recent ecotoxicological studies suggest a relationship between freshwater contamination and increasing abundances of motile diatoms (potentially able to move). The capacity to escape would present advantages to species in polluted environments. However, actual motility as a response to toxicants had not been described and required experimental validation. We designed a specific experiment to assess how a field-isolated diatom (Gomphonema gracile) distributes energy to in situ resistance (increased population growth or photosynthesis) and escape (behavioral changes), when exposed to increasing concentrations of the herbicide metolachlor. We report here the dose-time dependent responses of G. gracile populations. They coped with low contamination by... |
| Tipo: Text |
Palavras-chave: Diatoms; Physiology; Behavior; Pesticide exposure; Motility; CASA. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36521/35081.pdf |
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