The applicability of micro fluid segments for studying the behaviour of multicellular systems, in particular embryonic development, has been investigated. It was found that eggs from the zebrafish Danio rerio can be introduced into micro fluid segments without serious damage by using perfluoromethyldecalin (PP9) as the carrier liquid and Teflon (PTFE) as the tube material. The development processes of fish embryos were observed over a time period of 80 hours, until hatching time. After five days, the fish larvae were brought out of the micro fluid segments and transferred into breeding reservoirs. Effects of the membrane-damaging anionic surfactant sodium dodecyl sulfate (SDS) alone and SDS with the addition of CuCl(2) (copper(II) chloride) were investigated. By analyzing different end points, we found inhibiting and also supporting effects on the development of the embryos. Low SDS concentrations with and without copper(II) ions were supportive, while higher SDS concentrations led to negative impacts on the development of the embryos. The results showed that automated micro screening processes with complex biological systems can be performed using microfluidic systems and are applicable for future toxicological and drug screening studies.

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The Brachyura, within the decapod crustaceans, is one of the most species-rich taxa with up to 10 000 species. However, its phylogenetic history, evolution and fossil record remain subjects of controversy. In our study, we examined the phylogenetic relationships of the Brachyura based on morphological characters of the foregut. The cladistic analysis supports a monophyletic Brachyura including the Dromiidae and Raninidae. A clade comprising Dromiidae and Dynomenidae forms the most basal assemblage within the Brachyura, followed by the Homolidae and Latreilliidae. As a result, neither Podotremata nor Archaeobrachyura form a clade. In contrast, foregut data suggest that the classical taxon Oxystomata, comprising Calappidae, Parthenopidae, Dorippidae, Leucosiidae, Cymonomidae and Raninidae, is monophyletic. This makes the Heterotremata paraphyletic or polyphyletic. A newly established taxon, Neobrachyura, embraces some representatives of the Heterotremata and the monophyletic Thoracotremata.

The complexity of the brachyuran foregut, in particular the foregut ossicles and gastric teeth, were investigated and documented in 66 brachyuran taxa employing a new staining method. The brachyuran groundpattern is proposed to consist of 41 ossicles. Most of the ossicles show a very conservative pattern with only a few variations. A previous classification scheme proposed by Nauck (1880) with the grouping of the recent brachyuran crabs in Heterodontea and Cyclodontea is not supported by this study. The study also shows that the Heterodontea and Cyclodontea are not monophyletic.