Tejedo Miguel
Estación Biológica de Doñana, C.S.I.C., Apdo. 1056, 41080, Sevilla, Spain.
Oecologia. 1992 May;90(2):294-296. doi: 10.1007/BF00317189.
A trade-off between size and number of offspring was not found for females of similar sizes of the natterjack toad (Bufo calamita). Moreover, for large females, clutches with higher number of eggs had larger eggs as well. This suggests that larger females produce more numerous and larger eggs because they potentially have more energy available for reproduction. Egg size diminished allometrically with clutch size. Egg size, however, did not increase offspring fitness. Therefore, this allometric decrease may be considered a consequence of phylogenetic constraints rather than a result of optimizing selection.
在黄条蟾蜍（Bufo calamita）体型相似的雌性个体中，未发现后代数量与大小之间存在权衡关系。此外，对于体型较大的雌性个体，卵数较多的一窝卵也更大。这表明体型较大的雌性会产出更多数量且更大的卵，因为它们可能有更多能量可用于繁殖。卵的大小随窝卵数呈异速生长而减小。然而，卵的大小并未提高后代的适应性。因此，这种异速生长的减小可能被认为是系统发育限制的结果，而非优化选择的结果。
