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| Lemee, R; Boudouresque, Cf; Gobert, J; Malestroit, Pascale; Mari, X; Meinesz, A; Menager, V; Ruitton, S. |
| Experiments in aquaria have shown that the feeding behaviour of the sea urchin Paracentrotus lividus in presence of the green alga Caulerpa taxifolia varies during the year. In summer, the alga is strongly avoided and is not consumed. in winter and spring, although the alga is only moderately appreciated, its consumption is significant, but it is hardly or not at all absorbed. These results are confirmed by content analysis of the digestive tract of P. lividus sampled in situ in an area colonized by C. taxifolia. The sea urchins' feeding behaviour is linked to the presence of toxic and repellent secondary metabolites of C. taxifolia, caulerpenyne in particular. |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20483/18153.pdf |
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| Pedrotti, Ml; Marchi, B; Lemee, R. |
| The biological activity of a methanolic extract of the introduced species Caulerpa taxifolia and caulerpenyne (main secondary metabolite of the alga) was tested on embryogenesis, pluteus and metamorphosis stages of the sea urchin Paracentrotus lividus. The bioassays revealed different levels of toxicity according to the egg and larval development stages. Larval development was the most sensitive phase, followed by gastrulation. Methanolic extracts at a concentration of 1.0 mu g ml(-1) and caulerpenyne at a concentration of 100 ng ml(-1) (300 nM) tested on young larvae (4-arm stage) cause death within four hours. The same concentrations of methanolic extract, tested on eggs, blocked cleavage up to early blastula stage, whereas a double concentration of... |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20484/18154.pdf |
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