Literaturdatenbank
Literaturdatenbank |
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Casares, M., Rübel, G. A., & Honegger, R. E. (1997). Observations on the female reproductive cycle of captive giant tortoises (geochelone spp.) using ultrasound scanning. Journal of Zoo and Wildlife Medicine, 28(3), 267–273.
Added by: Admin (14 Aug 2008 22:46:40 UTC) Last edited by: Beate Pfau (01 Jan 2010 15:31:57 UTC) |
| Resource type: Journal Article BibTeX citation key: Casares1997a View all bibliographic details  |
Categories: General Keywords: Aldabrachelys, Aldabrachelys dussumieri, Aldabrachelys gigantea, Chelonoidis, Chelonoidis nigra, Fortpflanzung = reproduction, Geochelone, Schildkröten = turtles + tortoises, Testudinidae, Untersuchungsmethoden = examination method, Veterinärmedizin = veterinary medicine Creators: Casares, Honegger, Rübel Collection: Journal of Zoo and Wildlife Medicine |
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| Abstract |
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Geochelone gigantea nigra Testudinidae Dipsochelys dussumieri The reproductive activities of one adult female Galápagos tortoise (Geochelone nigra) and three adult female Aldabra tortoises (Geochelone gigantea) were monitored over 2 yr using ultrasound scanning. A nonrestraining technique of tactile stimulation was used for all examinations. Developing, preovulatory, and atretic ovarian follicles, as well as eggs at various stages of shell deposition, were identified and measured. In G. nigra, follicles became preovulatory at a diameter of 40-42 mm and eggs were laid 34-84 days (mean = 55.6, n = 5) after the thin-shelled eggs were first detected in the oviducts. Geochelone nigra was capable of retaining eggs, with the shell already formed, until the next breeding season. No eggs have been produced by G. gigantea during their stay in Zürich Zoo although follicles of 38-40 mm have been observed frequently in two animals. Added by: Admin Last edited by: Beate Pfau |