Die Embryonalentwicklung der Paradiesschnecke ... - TOBIAS-lib

Kapitel 2
Methods
The experiments were conducted on the basis of the M. cornuarietis embryo
test (MariETT) developed by Schirling et al. (2006) and modified
as described below. For a detailed description of material, techniques and
keeping of M. cornuarietis in aquaria see Osterauer et al. (2009, 2010a) and
Sawasdee and Köhler (2009, 2010). Scanning-electron micrographs and histological
sections were compared to the light microscopic observations of M.
cornuarietis embryonic development as analyzed in detail by Demian and
Yousif (1973a–d, 1975). All experiments were conducted in the laboratories
of the Institute of Evolution and Ecology, Tubingen University, between 17
June 2008 and 24 July 2008 (SEM) and 14 January 2010 and 3 August 2010
(histology). All animal care regulations and legal requirements were adhered
to.
Rearing of shell-less M. cornuarietis
On the first day of the experiment, all freshly deposited egg clutches were
carefully removed from the aquaria; the single eggs were separated from each
other using a razor blade and were then distributed into Petri dishes in a way
that all Petri dishes received 30 eggs. Petri dishes were made from polystyrol
and had a diameter of 94 mm. They were filled with the test solution, or,
for the water control, aquarium water.
For platinum 2+ exposure, a solution of nominally 200 µg/l platinum chloride
(corresponding to a real concentration of 163.4 ± 2.7 µg Pt/l, Osterauer
et al., 2010b) was used, made from one liter aquarium water and 200 µl platinum
chloride standard solution (platinum standard, Ultra Scientific, Wesel,
Germany, 1,000 µg/ml, Matrix: 98% water, 2% HCl). The Petri dishes were
kept at 26 ◦ C in a climate chamber at a light–dark regime of 12:12 h. The
test solutions were changed daily. Some shell-less embryos were transferred
to aquarium water after completion of embryonic development, and raised.
Pictures taken of living shell-less M. cornuarietis were edited in GIMP
(scaling, rotating, and cropping), labeling was added in Inkscape.
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