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| Natura: | Artículo científico |
| Lingua: | en |
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Academia Brasileira de Ciências
2003
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| Accesso online: | https://www.redalyc.org/articulo.oa?id=32775402 |
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Sommario:
- On clutch size and hatching success of the South American turtles Podocnemis expansa (Schweigger, 1812) and P. unifilis Troschel, 1848 (Testudines, Podocnemididae) Paulo Emilio Vanzolini Multidisciplinaria (Ciencias Naturales y Exactas) clutch size size theory optimal egg hatching success Podocnemis expansa Data on clutch size and hatching success of P. expansa were gathered for seven beaches traditionally usedby the species and re-analyzed statistically by means of regression analysis, of the number of eggs on thenumber 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 presentedgeographic 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 onesample, from Iquitos, had less than 90% success. The outstanding fit of the clutch size regressions leads oneto consider egg volume variability, which was found to be high in both species, in contradiction with currentoptimal egg size theory. 2003 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32775402 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.4 Vol.75