How to destroy a snail! - Problems and solutions working with histological samples of micro-scaled gastropods.
4. Graduiertenforum der Fachgruppe Morphologie der DZG, München, abstracts
|Type of Publication:||Congress Contributions and Posters|
Morphological and anatomical data are crucial to shed some light onto the polyphyletic assemblage of skeneimorph vetigastropods. Skeneimorph gastropods (Mollusca: Vetigastropoda) are small (diameter 1-5 mm) marine snails from shallow waters down to abyssal depths (e.g. hot vents, natural wood fall). To gain those data sets a lot of working steps are needed and multiple problems might occur: The material has to be plastic embedded, serial sectioned with diamond or glass knifes, stained and sealed. Even before that point the samples can be damaged massively, e.g. by freeze-storing or due to coagulation of the blood. Plastic embedding of complete animals, especially when larger than 2.5 mm, needs an extended retention time during drying in the rising acetone/alcohol set, otherwise the plastic will not penetrate the sample constantly - high air humidity also can impede a constant penetration. Mineral particles and solid gut/intestine content are a big problem when serial sectioning is performed. On the one hand the knives (diamond knifes are expensive) could be destroyed, on the other hand the sections will look strange. When not exchanged quite often, glass knifes can also produce broken slices. Some sealing detergents (e.g. cedar oil) can decolour the stained samples completely within one decade. During sealing sometimes some detergent can soak between cover glass and balance weight - when removing the latter the cover glass breaks. Among the samples investigated, the following artefact occasion¬nally occurs: When the animals are anesthetized and fixed, the blood coagulates and expands, resulting in an “exploded” aspect of the heart. To sum up, this poster should give an overview to problems that occurred during our research and work with dozens of different section series on lots of genera of microgastropods. We want to present some helpful approaches for working with such animals.