Karyological relationships between the Cryptobranchid salamanders

Summary The 3 living Cryptobranchids (Andrias japonicus, A. davidianus andCryptobranchus alleganiensis) show 2n=60 and nuclear DNA amounts of respectively 92.9, 100.1 and 112.5 pg. Karyologically, the 2 genera differ in the morphology of 2 chromosome pairs. The hypotheses are advanced that either theCryptobranchus karyotype is derived from that ofAndrias through an unequal translocation, or the karyotypes of both genera are derived from that of a common (perhaps hynobiid) ancestor with at least 62 chromosomes.Research supported by a contribution from the Italian C.N.R.