We studied reciprocal hybrids of Mus musculus musculus and M. m. domesticus. These two subspecies of house mouse were found to differ in their social behaviour, the former being less aggressive than the latter. The paternal effect on aggression (observed repeatedly in laboratory mice) was not found. However, F2 generation mice were less aggressive than those from the F1 generation, and the maternal effect was also significant in a homogenous test set.
We studied growth rates in four eublepharid species in which mass-metabolic allometry was available from the literature. The lizards were reared in a common garden environment and the growth data were analysed using the production/growth model (W e s t et al. 2001: Nature 413: 628–631). The model fits well our data in eublepharid geckos, and thus the applicability of this model to reptile growth was demonstrated. Estimated values of growth-rate parameter (a) fell within the range known in other ectotherm animals. As expected from theoretical parameter derivation, species sharing the same mass-metabolic allometry (Eublepharis macularius, Coleonyx mitratus, Coleonyx elegans) show comparable a in spite of considerable interspecific differences in asymptotic body mass. Moreover, in accordance with theoretical predictions, the only examined species with the elevated metabolic scaling, i.e. Coleonyx brevis, showed higher a than the other species.