Chromosome Evolution of Amphibians in Thailand

Abstract

The chromosome evolution of 3 orders of amphibians in Thailand namely, Gymnophiona, Caudata and Anura were studied. The most primitive group is order Gymnophiona which has 2n (diploid) =42 including 20 microchromosomes and 22 macrochromosomes, whereas the other including only macrochromosomes. The Caudata karyotype is 2n=24 and only bi-armed chromosomes were found. The order Anura was divided into two suborders, Mesobratachia and Neobratachia. The suborder Mesobratachia still has quite primitive karyotype, 2n=24-26 which consisted of both bi-armed and mono-armed chromosomes. The suborder Neobratachia has advanced karyotypes, 2n=22-28 which consisted only of bi-armed chromosomes. The cytogenetic study can help to better understand the evolution of amphibians.