Archiv/Abstracts 2010

Veröffentlicht: 25.07.2010

Schildkröten im Fokus, Bergheim 7 (3) 2010: 10–25

Lithophagie bei Schildkröten

Lithophagy in Chelonians.

Gerhard Jennemann, Kirchhain-Stausebach

Abstract

Very often keepers of tortoises observe that tortoises ingest stones or sand and frequently argue that they, like birds, need stones for optimal digestion. On the other hand coproliths are sometimes the cause of death as revealed by necropsy. Therefore, the question of whether tortoises need stones for their digestions needs some clarification. In addition very often keepers and veterinarians argue that the hydrochloric acid production in the stomach dissolves limestone and contributes to the digestion of minerals. Here I provide an histological overview by comparing the alimentary tract (and especially the stomach and proximal small intestine) of grain eating, gizzard bearing birds such as doves with those of the tortoise Testudo hermanni and the turtle Emys orbicularis, as well as with the stomach of omnivorous humans, insectivorous hedgehogs or herbivorous mammals such as roe deer and guinea pig. The histological and histochemical data provide clear evidence that the digestion of the tortoise is not supported by stones as it is known for certain bird species. Furthermore HCl producing parietal cells which are characteristic for the stomach of mammals as well as the characteristic Brunner glands of the duodenum are lacking in European tortoises and turtles which indicates that tortoises and turtles do not form HCl within the stomach. In addition I refer briefly to natural habitats of European tortoises in order to explain their adaptive behaviour to feed on gravel when they suffer from calcium deficiency or when they are affected by parasites.

Key words

Alimentary tract, histology, histochemistry, glandular stomach, gizzard, intestine, parietal cells, Brunner gland, lithophagy, psammophagy, coproliths, birds, Reptilia, Chelonia, Testudines, Testudinidae, Testudo graeca, Testudo hermanni, Emydidae, Emys orbicularis, humans, hedgehog, deer, guinea pig.

Authors

Gerhard Jennemann
Alter Kirchweg 11
35274 Kirchhain-Stausebach
Internet: www.sciencephoto.de




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