Literaturdatenbank
Literaturdatenbank |
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Vanzolini, P. E. (2003). On clutch size and hatching success of the south american turtles podocnemis expansa (schweigger, 1812) and p. unifilis troschel, 1848
(testudines, podocnemididae). Annals of the Brazilian Academy of Sciences, 75(4), 415–430.
Added by: Admin (14 Aug 2008 20:36:28 UTC) |
| Resource type: Journal Article BibTeX citation key: Vanzolini2003 View all bibliographic details  |
Categories: General Keywords: Fortpflanzung = reproduction, Habitat = habitat, Podocnemididae, Podocnemis, Podocnemis expansa, Podocnemis unifilis, Schildkröten = turtles + tortoises, Südamerika = South America, Zeitigung = incubation Creators: Vanzolini Collection: Annals of the Brazilian Academy of Sciences |
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| Abstract |
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Data on clutch size and hatching success of Podocnemis expansa were gathered for seven beaches traditionally used by the species and re-analyzed statistically by means of regression analysis, of the number of eggs on the number of females (or nests) and of the number of young on the number of eggs. All regressions were linear, passed through the origin and had excellent fits. Average clutch size varied from 75 to 123, and presented geographic differentiation: (i) Rio Orinoco, (ii) Rio Trombetas + Rio Branco and (iii) Rio Juruá + Rio Purus. Average hatching success was ca. 83%. In P. unifilis there was also geographic variation in clutch size, the Iquitos area showing the highest values. Hatching success of P. unifilis was uniformly high: only one sample, from Iquitos, had less than 90% success. The outstanding fit of the clutch size regressions leads one to consider egg volume variability, which was found to be high in both species, in contradiction with current optimal egg size theory.
Added by: Admin |