Literaturdatenbank
Literaturdatenbank |
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Mitrus, S. (2003). The calcareous layer eggshell of the turtle emys orbicularis: ultrastructure and composition. Italian Journal of Zoology, 70(1), 13–16.
Added by: Sarina Wunderlich (24 May 2009 21:32:40 UTC) |
| Resource type: Journal Article BibTeX citation key: Mitrus2003b View all bibliographic details  |
Categories: General Keywords: Emydidae, Emys, Emys orbicularis, Fortpflanzung = reproduction, Schildkröten = turtles + tortoises, Zeitigung = incubation Creators: Mitrus Collection: Italian Journal of Zoology |
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| Abstract |
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The calcareous layer of the European pond turtle (Emys orbicularis) eggshell was examined by scanning electron microscopy with an energy dispersion spectrometer and by diffractometry. The layer is composed of well-distinguished shell units consisting of needle-like crystallites radiating outwards from a core. Pores in the eggshell are rare, although structures similar to very small and rounded “pores”; on the outside surface were found. There are differences in appearance of the inner surface between shell units of hatched eggs and those of unfertilised eggs: in the former, flat, conical depressions are present, while in the latter the surface is almost flat. This suggests that the developing embryo derives calcium from the eggshell, which consists mostly of calcium carbonate in aragonite form. The analysis of dried eggshell showed the presence of about 38% (percent of weight) of calcium, 45% of oxygen, 13% of carbon and S, Na, P, Mg, K, Fe, Zn, Cl, Al, Cu and Si in traces.
Added by: Sarina Wunderlich |