[Amino acid chemoreception and motor activity in the frog Rana lessonae (Amphibia)]

The changes motor activity in the frog Rana lessonae in clean water depends on the type amino acids, stimulating chemoreceptors. Reactions orientations (as reaction of recognizing) in adult frog are caused by only amino acids constantly present in ponds water, while amino acids, only periodically appearing in ponds water, are not caused. Amino acids with more short chains of carbon atoms in the molecules (C3-C4) are more effective (with significance p < 0.01) in change motor activity, than amino acids with more long chains (C5-C6) of the molecules. This law is characteristic (on literature by data) for reactions of taste receptors in fishes. It is possible that chemoreceptors of Rana lessonae, perceiving amino acids and initiating changes in behavior this animal, resembles the taste receptors in fishes.