Skeletal morphology and fluctuating asymmetry of the European green toad, Bufotes viridis, in contrasting habitats

Abstract

Current environment changes and global amphibian decline suggest specific responses assuming urbanisation potential of the species. Amphibians are generally considered to be suitable bio-indicators of environmental health due to their ecological requirements. Therefore, fluctuating asymmetry (FA), a measure of small random deviations from bilateral symmetry is used for assessing morphological disruptions and parallelly the environment health. We measured the snout-vent length and lengths of five skeletal traits of limbs (humerus, radioulna, femur, tibiofibula, calcaneus) among the five European green toad populations from two contrasting habitats (urban and rural). We did not confirm our hypothesis that urban populations would exhibit higher level of FA as an indicator of higher environmental stress comparing to rural populations. However, asymmetry measured on forelimb bones was significantly larger than on hindlimbs. In addition, one urban population had significantly longer limbs comparing to the other sites.