Amphibian optokinetic after nystagmus: properties and comparative analysis in various species.

Optokinetic nystagmus and after nystagmus were studied in six amphibian species, three urodeles and three anurans. It was demonstrated that two of the urodeles, Hydromantes italicus and Salamandra salamandra, display a relatively well-developed optokinetic after nystagmus, which is less pronounced in Bombina variegata and nearly absent in Bufo bufo, Rana temporaria, and Tylototriton verrucosus. These results indicate a certain degree of velocity storage in the optokinetic reflex of some amphibians.