Karyotypic analyses of four species of Ambystoma (Amphibia, Caudata) that have been implicated in the production of all-female hybrids

Abstract

Four salamander species of the genus Ambystoma hybridize in the Great Lakes region of eastern North America. The hybrids are mostly polyploid and virtually all-female. Basic chromosomal morphology and C-banding patterns of Ambystoma laterale, A. jeffersonianum, A. texanum, and A. tigrinum tigrinum were examined in an attempt to find some markers that would be useful to recognize genomic constitution of the hybrids. Several minor morphological differences were found among the karyotypes of the four species, but none were of sufficient magnitude to unambiguously assign genomic content in a hybrid. There was no evidence of sexually dimorphic bands in any of the species.Key words: chromosomes, Ambystoma, C-bands, hybridization, amphibia.