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(18-28) Developement of a sediment bioassay with the netted whelk Nassarius reticulatus (Gastropoda: Prosobranchier). Tillmann, Michaela*,1, Schulte-Oehlmann, Ulrike2, Duft, Martina1, Markert, Bernd1, Oehlmann, Jörg2, 1 InternationalGraduate School Zittau, Ecotoxicology, Markt 23, Zittau, Germany2 J.-W.-Goethe University Frankfurt, Ecotoxicology, Siesmayerstrasse 70, Frankfurt/Main, Germany ABSTRACT- For the detection of endocrine disruptors, there are only few test systems available. Most of the classic methods to indicate estrogenic or androgenic compounds are relatively insensitive and only suitable to assess hormonal activities at high concentrations. Furthermore, most methods are focussed on the identification of (xeno-)estrogens. Sediments, which are often a sink for lipophilic compounds, exhibit a high ecotoxicological relevance. However, tests for the detection of the endocrine potential of sediments are rare. For an endocrine evaluation of sediments special emphasis should therefore be laid on typically benthic organisms which are in direct contact with the contaminations. Consequently our aim was to develop an organismic biotest for the identification of androgenic and estrogenic disruption - simultaneously in one test. Additionally, hormone-mimetic chemicals should be detected in laboratory tests with artificial sediments as well as in field samples. One response to androgenic pollution is the expression of the virilisation phenomenon "imposex" in prosobranch gastropods. Imposex is characterised as the additional formation of male reproductive organs like penis and/or vas deferens in females. The netted whelk Nassarius reticulatus is one of the marine prosobranch species expressing imposex. In this presentation, the phenotypic imposex expression in N. reticulatus will be demonstrated by means of studies with various androgens as well as real environmental samples. The so-called "uterotrophic snail assay" will be presented as a possible endpoint to give first information on the estrogenic potential of spiked artificial sediments and field samples. Key words: sediment bioassay, endocrine, imposex, Nassarius reticulatus |
