Specific chemosignals (pheromones) have an important role in the antipredator behaviour in amphibians and other vertebrates. However, relatively little is known about the occurrence of chemical alarm cues just in amphibians. The site of chemosignals perception is vomeronasal system. The presence of the vomeronasal system in aquatic amphibians indicates that it did not arise as an adaptation to ...

Phylogenetic relationships among the species of true frogs (Rana) from North, South, and Central America were investigated based on the sequences of approximately 2 kb from the mitochondrial genome, sampled from most of the described species, as well as eight undescribed species. This analysis, combined with previous studies of the phylogeny of New World Rana, served as the basis for a revised ...

In central Europe, the hybridogenetic waterfrog Rana esculenta, a hybrid between Rana ridibunda and Rana lessonae, lives in sympatry with one of its parental species, the poolfrog Rana lessonae. As R. esculenta has to backcross constantly with R. lessonae in order to produce viable offspring, this coexistence is obligatory for R. esculenta. Since R. esculenta has a higher primary fitness than R...

The nucleotide sequences of the D-loop region, the light (L) strand replication origin and the seven tRNA genes of the Rana catesbeiana mitochondrial genome were determined and compared with their counterparts of other higher vertebrate mitochondrial genomes. The results obtained are as follows: 1) The D-loop region consists of 2,187 nucleotides and is flanked by the cyt b gene on the 5' end an...

In the previous paper of this series (Remp, '53) it was reported that tadpoles of Rana pipiens would live up to 6 days at room temperature after excision of heart at Shumway stage 22 or 23. Because of the obvious differences between anuran and urodele larvae in form and rate of development, the experiment was repeated on Amblystoma punctatum at Harrison stage 40, 41 o r 42 (Kemp and Quinn, '51)...